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  • 1970-1974  (2,389)
  • 1965-1969  (1,820)
  • 1960-1964  (1,184)
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  • 1
    Electronic Resource
    Electronic Resource
    On different patterns of dendritic bundling in the cerebral cortex of the cat (1974)
    Springer
    Anatomy and embryology 143 (1974), S. 115-126 
    Details
    ISSN: 1432-0568
    Keywords: Cerebral cortex ; Apical dendrites ; Dendritic bundles ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In frontal, horizontal and sagittal paraffin sections through the cat's brain regional differences in the pattern of dendritic bundling have been investigated. It is shown that in the gyrus splenialis and suprasplenialis 2–5 apical dendrites of layer IV pyramids approach each other to form vertical bundles which run straight through layer IV. In the posterior sigmoid gyrus, on the other hand, most apical dendrites arising from the pyramidal cells bifurcate immediately above layer V and give rise to obliquely running branches which cross each other before turning upwards and joining other dendrites to take part in the formation of bundles. In this region the dendritic tree of the pyramidal cells seems to be characterized by an unexpectedly high degree of directional specialization.—In functional terms the findings can be summarized by stating that in the visual and sensorimotor regions of the cat's cerebral cortex basic differences exist in the relation between the apical dendrites of layer V pyramids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00525764
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  • 2
    Electronic Resource
    Electronic Resource
    Crossed reticulo-reticular projections in the medulla, pons and mesencephalon (1974)
    Springer
    Anatomy and embryology 143 (1974), S. 127-134 
    Details
    ISSN: 1432-0568
    Keywords: Reticular formation ; Crossed connections ; Autoradiography ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injection of radioactive leucine in various regions of the brain stem reticular formation has revealed the presence of ample crossed reticulo-reticular connections in the cat. The terminal area for the crossed fibers are almost mirror images of the injected sites. The findings made is another example that hitherto unknown fiber connections can be demonstrated by axoplasmic protein tracing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00525765
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  • 3
    Electronic Resource
    Electronic Resource
    Evolution ultrastructurale du labyrinthe de placenta de chatte (1974)
    Springer
    Anatomy and embryology 146 (1974), S. 1-20 
    Details
    ISSN: 1432-0568
    Keywords: Placenta ; Cat ; Differentiation ; Function ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'ultrastructure du labyrinthe de placenta de chatte a été étudiée du 45e au 63e jour de gestation. Cette formation endothéliochoriale est composée: d'un endothélium maternel hypertrophié et de cellules géantes déciduales; d'une couche de «substance inerte interstitielle»; du trophoblaste constitué d'une assise syncytiale continue (syncytiotrophoblaste) et d'une assise cellulaire discontinue (cytotrophoblaste); d'un endothélium foetal accompagné de son environnement mésenchymateux. Les capillaires foetaux envahissent progressivement le syncytiotrophoblaste. L'hypertrophie de l'endothélium maternel diminue en fin de gestation; de ce fait la distance, séparant le sang maternel du sang foetal, peut atteindre en certains points 2 μ. L'endothélium maternel, le syncytiotrophoblaste et l'endothélium foetal présentent des signes ultrastructuraux d'un rôle de transfert. La «substance inerte inerte interstitielle», qui sépare les tissus d'origine maternelle des tissus d'origine foetale, est constante mais d'épaisseur variable; elle est spécifique des structures endothéliochoriales. Les cellules géantes déciduales, dont le nombre diminue en fin de gestation comportent parfois un ou plusieurs «corps glycogéniques». Le syncytiotrophoblaste, siége d'activité de biosynthése de stéroïdes, est riche en ergastoplasme, ce qui autorise à postuler la synthése d'hormones protéiques.
    Notes: Summary The ultrastructure of feline placental labyrinth has been studied from the 45th to the 63rd day of gestation. The endotheliochorial structure is composed of: a thick hypertrophied maternal endothelium with giant decidual cells; an “interstitial inert substance”; a continuous syncytial layer (syncytiotrophoblast) and a discontinuous cellular layer (cytotrophoblast) of trophoblast; and a thin foetal endothelium with its surrounding mesenchyme. Foetal capillaries increasingly invade the syncytiotrophoblast. Maternal endothelial hypertrophy is reduced in the last days of gestation. Thus the interval between maternal and foetal bloods may in some areas become 2 μ, in late pregnancy. Foetal endothelium, syncytiotrophoblast, and maternal endothelium demonstrate ultrastructural features of transfer function. The “interstitial inert substance”, which separates maternal from foetal tissue was always evident though with variable thickness. The giant decidual cells which are reduced in late pregnancy, show one or several “glycogen bodies”. The syncytiotrophoblast, where some steroïd biosynthesis has been demonstrated, has an extensive rough endoplasmic reticulum suggestive of protein hormone synthesis activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341379
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  • 4
    Electronic Resource
    Electronic Resource
    Zur histogenese und cytogenese des tapetum lucidum cellulosum der katze (1974)
    Springer
    Anatomy and embryology 146 (1974), S. 141-156 
    Details
    ISSN: 1432-0568
    Keywords: Tapetum lucidum cellulosum ; Cat ; Development ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die postnatale Entwicklung des Tapetum lucidum cellulosum der Katze wird mit licht- und elektronenmikroskopischen Methoden untersucht. Bereits am ersten postnatalen Tag sind im Bereich des prospektiven Tapetum zwei Zellarten voneinander zu unterscheiden: 1. mesenchymale Bindegewebszellen und 2. prospektive Tapetumzellen, die durch elektronendichte Tapetumstäbchen gekennzeichnet sind. Die Mesenchymzellen unterteilen als parallel zur Retinaoberfläche ausgebreitete Zellplatten in der Choriodea am hinteren Augenpol den weiten extracellulären Raum in 20–25 etwa 5 μm hohe Schichten. Die Tapetumzellen liegen zwischen den Mesenchymzellplatten und wachsen im Verlaufe der ersten vier postnatalen Wochen innerhalb der Schichten in die Breite, bis sie den extracellulären Raum vollständig ausfüllen und als polygonale Zellen direkt aneinander grenzen. Im weiteren Verlauf der Entwicklung werden die Mesenchymzellplatten rückgebildet, so daß bei der adulten Katze die Tapetumzellschichten direkt übereinander liegen und nur von Netzen elastischer und kollagener Fasern getrennt sind. Die von einer Elementarmembran umgebenen Tapetumstäbchen enthalten einen elektronendichten, in den ersten postnatalen Wochen mit einer Periode von 100 Å quergestreiften Kern. Zunächst nehmen sie an Zahl und Länge zu und füllen am Ende der vierten postnatalen Woche, zu Bündeln von parallel verlaufenden Stäbchen geordnet, das Cytoplasma der Tapetumzellen. Dann nehmen die Tapetumstäbchen an Dicke zu, und ihre Querstreifung wird von einem elektronendichten Material überlagert. Die Entwicklung der Tapetumstäbchen hat eine starke Ähnlichkeit mit der in der Literatur beschriebenen Entwicklung von Melanosomen in Melanocyten. Das Tapetum lucidum cellulosum wird als ein dichter Verband hochdifferenzierter extrakutaner Melanocyten angesehen.
    Notes: Summary The postnatal development of the tapetum lucidum cellulosum of the cat was studied by light and electron microscopy. Already by the first postnatal day two cell types can be distinguished in the prospective tapeta area: 1. mesenchymal cells and 2. prospective tapetal cells, characterized by electron dense, membrane bound, rod-like inclusions. The flattened mesenchymal elements form 20–25 separate layers of cells, which are arranged parallel to the surface of the retina, subdividing the extracellular space of the chorioidea at the posterior pole of the eye into 5 μm high compartments. These compartments contain the tapetal cells which enlarge (in their longitudinal axis) during the first four weeks post partum until they occupy the extracellular space almost completely. At this stage, the tapetal cells are polygonal in shape and closely attached to each other. During the subsequent period of development there is a gradual involution of the mesenchymal cell plates. Thus, in adult cats the individual layers of tapetal cells are only separated from each other by networks of collagen and elastic fibers. The tapetal rods are bound by unit membranes and contain an electron dense core which, during the early postnatal weeks, exhibits a periodic cross-striation (100 Å). The tapetal rods increase in number and length during the first four weeks post partum; by the end of the fourth week, they occupy the whole cytoplasm of the tapetal cells. Parallelly arranged rods are grouped into individual bundles coursing inside the cytoplasm in different directions. Thereafter, the tapetal rods increase in thickness and their cross-striation becomes obscured by an electron dense material. This development of the tapetal rods closely resembles that of melanosomes. Thus the tapetum lucidum cellulosum can be regarded as a compact tissue made up of modified extracutaneous melanocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315591
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  • 5
    Electronic Resource
    Electronic Resource
    Function and interaction of on and off transients in vision II. Neurophysiology (1974)
    Springer
    Experimental brain research 19 (1974), S. 507-521 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; LGN ; Transients ; Antagonistic inhibition ; Sensory storage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal responses to interruptions of light stimuli were studied in 58 X-type and 7 Y-type LGN relay cells with intra- and extracellular recording techniques. The responses to interruption were then compared with responses to either appearing or disappearing light stimuli which had the same luminance and size as the interrupted stimulus. The extent to which responses to interruption differed from those to appearance and disappearance was studied as a function of the interstimulus interval (ISI), the duration of the stimulus before the interruption (t1) and after the interruption (t2). Responses to stimuli appearing after interruptions of up to 500 msec were weaker than those to appearance and disappearance. This difference decreased with increasing ISI. The difference between responses to appearance and interruption increased as t2 decreased, and decreased as t1 decreased. The reverse was true for the difference between responses to disappearance and interruption. Stimulation of the mesencephalic reticular formation consistently reduced the difference between responses to appearance and disappearance compared with those to interruption for all stimulus conditions. These results are discussed in the context of the psychophysical study presented in the preceding paper. It is shown that the neuronal reactions are reflected in detail by the ability of humans to detect appearances and disappearances that occur during interruptions. EPSP sequences recorded from LGN relay cells and relay cell responses conditioned by reticular stimulation suggest that the differentiation of responses to interruption and change partially occurs already in the retina. This differentiation is subsequently enhanced by antagonistic inhibition in the LGN. It is proposed that these inhibitory interactions at peripheral sites of the visual pathway store visual information and serve to reduce the redundancy of responses to short interruptions of the visual input. Centrifugal modulation of LGN inhibition is proposed to control the trade off between temporal integration and temporal resolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236114
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  • 6
    Electronic Resource
    Electronic Resource
    Reflexes in postganglionic fibres within skin and muscle nerves after noxious stimulation of skin (1974)
    Springer
    Experimental brain research 20 (1974), S. 125-134 
    Details
    ISSN: 1432-1106
    Keywords: Somato-sympathetic reflexes ; Cutaneous and muscle postganglionic neurones ; Noxious stimulation of skin ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Somomato-sympathetic reflexes in postganglionic neurones to skin and muscle induced by noxious stimulation of skin were studied in cats anaesthetized with chloralose. The reflexes were elicited by mechanical damaging stimuli and by temperature stimuli of more than 45°C. 2. In most cutaneous units the spontaneous activity was depressed during noxious stimulation of skin. Some cutaneous units were excited or showed mixed responses. The depression of the spontaneous activity was maximal from the skin area which was innervated by the cutaneous postganglionic neurones and much weaker or not elicitable from other skin areas. 3. Most muscle units were excited during noxious stimulation of skin. This excitation could be elicited from all over the body surface. 4. The effective cutaneous afferent fibres which are involved in these reflexes are the Group III axones which are excitable by mechanical damaging stimuli and the Group IV axones which are excitable by mechanical damaging and/or by thermal noxious stimuli. 5. These investigations reveal that the somato-sympathetic reflexes have opposite organization in cutaneous and muscle postganglionic fibres. The reflex patterns are discussed in relation to a possible central organization of the sympathetic nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234007
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  • 7
    Electronic Resource
    Electronic Resource
    Role of visual experience in the development of optokinetic response in kittens (1974)
    Springer
    Experimental brain research 20 (1974), S. 297-302 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Selective rearing ; Maturation ; OKN ; Perception of motion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Kittens reared in the dark from birth were exposed one hour a day between the 4th and the 10th week of age, to a visual environment which consisted exclusively of vertical edges moving horizontally at a constant speed, and always in the same direction. Total exposure time varied between 10 and 60 hours. 2. At the 12th week of age, optokinetic nystagmus (OKN) in response to displacements of the visual field, was tested. Displacements in the direction that the kittens had experienced during the exposure period elicited immediately an OKN, the frequency of which was related to the speed of the moving pattern. Displacements in the opposite direction elicited a poorer response, only for slowly moving edges. When the speed of the displacement was increased, OKN failed to adapt and finally disappeared. 3. These results suggest the existence, in this type of visuomotor behavior, of a component built up by early visual experience (adaptative component) overlying another component pre-existing visual experience (pre-programmed component).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238319
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  • 8
    Electronic Resource
    Electronic Resource
    Attention in the cat: Electrophysiological and behavioural studies (1974)
    Springer
    Experimental brain research 21 (1974), S. 67-82 
    Details
    ISSN: 1432-1106
    Keywords: Sensory transmission ; Lateral geniculate nucleus ; Visual cortex ; Attentive behaviour ; Vigilance ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The behaviour of 6 cats was studied in a vigilance task. Each cat was trained to press a pedal on the floor of a training box. A waiting interval of fixed (FI) or variable (VI) duration then followed, after which a stimulus (S), a spot of light or a tone, was presented for a short period of time. The cat gave a correct response if, during this time, it pressed a panel. The animal was then rewarded with food. When an experiment had been completed using one S the cat was trained to respond to the other. The latency of response following the onset of S was measured for each waiting interval in the VI schedules. It was found that the longer latencies were associated with the shorter waiting intervals; that is, the cats responded more quickly to S as expectancy increased. Between the time the pedal and pand were pressed the optic tract (OT) was shocked not more than once and the response of the LGN and visual cortex recorded. The time at which the shock was delivered varied from 1 trial to the next. The responsiveness of the LGN and visual cortex did not vary during the waiting interval in either of the FI schedules or in the VI schedule in which S was a spot of light. However, in the VI schedule in which S was a tone, the responsiveness of the visual cortex to the thalamocortical input declined as the length of the waiting interval increased. No changes were observed at the LGN or in the presynaptic cortical response. These results contrast with those observed during changes in the level of arousal as assessed by the ECoG. When the ECoG passed from the synchronised to the desynchronised state there was an increase in the amplitude of the postsynaptic LGN response to the OT shock, but no change in the responsiveness of the cortex to the increased thalamocortical input. These changes in transmission in the visual pathways are discussed in relationship to the animal's behaviour and to the inferred state of attention.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234258
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  • 9
    Electronic Resource
    Electronic Resource
    Electrotonic coupling between motoneurones in the abducens nucleus of the cat (1974)
    Springer
    Experimental brain research 21 (1974), S. 139-154 
    Details
    ISSN: 1432-1106
    Keywords: Electrotonic coupling ; Antidromic responses ; Abducens motoneurone ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electrical stimulation of the abducens nerve provokes the classical true antidromic invasion of the abducens motoneurone and a depolarization which is often capable of generating full action potentials in the impaled motoneurone. Experiments studying these depolarizations suggest the existence of electrotonic coupling between the abducens motoneurones of the cat. Intracellular activity of the abducens motoneurones was recorded following intracellular stimulation of the impaled neurone and antidromic stimulation of the abducens nerve. Collision between the outgoing action potential and the antidromic volley differentiated the true antidromic spike from the depolarizations which can induce or not action potentials. The latency of the depolarization ranged between 100 and 1200 μsec. Collision demonstrated that the depolarization and the true antidromic action potential have an independent origin. The depolarizations and action potentials which are not conveyed to the motoneurone by its own axon are interpreted to be generated by electrotonic coupling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234386
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  • 10
    Electronic Resource
    Electronic Resource
    The lateral reticular nucleus in the cat I. Mossy fibre distribution in cerebellar cortex (1974)
    Springer
    Experimental brain research 21 (1974), S. 473-486 
    Details
    ISSN: 1432-1106
    Keywords: Lateral reticular nucleus ; Reticulocerebellar projection ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The areas of the cerebellar cortex receiving fibres from the mLRN (major portion of the lateral reticular nucleus comprising its parvi- and magnocellular parts) were determined by identifying the low-threshold spots on the cerebellar surface from which 286 mLRN neurones could be antidromically activated. 2. The mLRN fibres terminate bilaterally in the anterior lobe and pyramis, and ipsilaterally in the paramedian lobule. Some fibres terminate also in the rostral part of lobule VI but hardly any in other parts of the cortex. It follows that the mLRN projects almost exclusively to the classical spinal receiving areas. 3. Neurones in the parvi- and magnocellular parts project to similar cortical areas. 4. Two regions in the mLRN were distinguished on the basis of their different projection areas. Region A, a dorsolateral portion of the magnocellular part, projects to the ipsilateral parts intermedia of the anterior lobe and the ipsilateral paramedian lobule. Region B, a ventral portion of the parvi- and magnocellular parts, projects bilaterally to the pars intermedia and vermis of the anterior lobe and sparsely to the pyramis. 5. Neurones throughout the parvi- and magnocellular parts receive monosynaptic excitation from fibres ascending in the ventral part of the ipsilateral lateral funiculus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237166
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  • 11
    Electronic Resource
    Electronic Resource
    Vertical organization in the visual cortex (area 17) in the cat (1974)
    Springer
    Experimental brain research 21 (1974), S. 315-336 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex (area 17) ; Cat ; Columnar organization ; Retino-cortical scatter ; Intracortical connections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Responses of cortical cells in the cat's area 17 (central and paracentral area), recorded successively during electrode penetrations perpendicular to the surface, were averaged (PSTH). All cells recorded during one penetration were stimulated with the same stimulus, a slowly moving light or dark slit oriented optimally for the first cell recorded. Comparisons between successively recorded cells were completed by simultaneous recordings from two neurones with the same microelectrode tip. Eye movements as an error were excluded by simultaneous recording of a geniculate cell throughout a cortical penetration. 2. The centers of excitatory receptive fields (ERFs) of simultaneously or successively recorded cells during a penetration may be separated by more than 4°. The mean scatter around a column average is 0.81±0.99° in both directions. The scatter is independent of the recording depth. Whereas the optimal orientation of cells recorded during one penetration was generally similar, the optimal direction (forward and backward movement of an optimally oriented stimulus) was variable. 3. The ERF diameters as determined from the PSTH were between 〈0.5° and 7.5°. During each penetration, cells with small (up to 3.0°) and large (〉3.0°) ERFs could be discriminated. The inhibitory fields (determined with the conditioning method of Bishop, Coombs and Henry, 1971) were between 2.0 and 8.5° along both the optimal and the non-optimal orientation axis of a cell. The borders of inhibitory fields of cells collected during one penetration were also scattered though overlapping. 4. Response analysis of simultaneously and successively recorded cells with different stimuli indicated that, in spite of considerable ERF-overlap, cells with small ERFs had separate excitatory inputs and that intracortical excitatory connections between cells recorded during one penetration were improbable. 5. The ERFs of cells with large ERFs covered a field approximately corresponding to the fields of cells with small ERFs. But a convergent input from many small ERF cells to single large ERF cells was excluded because of the incompatible functional properties of both types of cells, which correspond to some extent to simple and complex cells respectively. 6. It is concluded that cells within cortical cylinders are not connected through excitatory contacts with each other and that most cells in area 17 are excited by individual excitatory geniculate or cortical inputs. Inhibitory connections seem to be the most important intracortical connections. 7. In an Appendix it is shown that anatomical and physiological data do not support significant excitatory convergence of specific geniculate afferents on cortical neurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235750
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  • 12
    Electronic Resource
    Electronic Resource
    The projection of the superior colliculus onto the reticular formation of the brain stem an experimental anatomical study in the cat (1974)
    Springer
    Experimental brain research 19 (1974), S. 1-19 
    Details
    ISSN: 1432-1106
    Keywords: Reticular formation ; Superior colliculus ; Cat ; Experimental anatomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following altogether 18 stereotactically placed lesions of different location and size in the superior colliculus the efferent fibres to the RF and their distribution were traced in silver impregnated, approximately serial sections (Nauta and Fink and Heimer methods), cut in the transverse, horizontal or sagittal plane. The projection to the mesencephalic RF was found to be almost completely ipsilateral, that to the pontomedullary RF largely contralateral. In the mesencephalic RF the fibres end in its dorsal half approximately. In the pons and medulla they supply only the medial 2/3 of the main RF, with two distinct maxima within the total field of termination. One maximum covers the rostral part of the nucleus reticularis gigantocellularis and the adjoining part of the nucleus reticularis pontis caudalis, the other occupies the rostralmost part of the latter and the caudal part of the nucleus reticularis pontis oralis. Of the precerebellar reticular nuclei the contralateral nucleus reticularis tegmenti pontis receives a distinct component of tectal fibres in a small area dorsomedially. Some fibres end in a restricted part of the nucleus reticularis lateralis and in the paramedian reticular nucleus. The tectoreticular projection appears to be organized according to the same principles as other afferents to the RF. In the main RF the areas of termination of the tectoreticular fibres coincide more or less with the areas of termination of corticoreticular, fastigioreticular and vestibuloreticular fibres. These common terminal areas are those which give off the bulk of reticulospinal fibres. Some functional implications of the pattern of organization in the tectoreticular projection are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233392
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  • 13
    Electronic Resource
    Electronic Resource
    Neuronal activity during eye movements in a visual association area of cat cerebral cortex (1974)
    Springer
    Experimental brain research 19 (1974), S. 467-477 
    Details
    ISSN: 1432-1106
    Keywords: Suprasylvian gyrus ; Cat ; Single neurons ; Eye movements ; Direction sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 270 single neurons from the anterior part of the middle suprasylvian gyrus (AMSS) were recorded in awake and non-paralyzed cats (Chronic preparation). 10% were unresponsive to visual stimulation, the remainder reacted well to moving visual stimuli. Half of the units tested were directionally selective. Horizontal, or downward preferred directions predominated. Most neurons were relative insensitive to changes of shape, orientation, contrast, and velocity of the visual stimulus. Some neurons preferred rapid (100°/sec) jerky movements, others required complex motions of irregular shapes, a few strongly preferred objects moving towards the animal in the midsagittal plane. 40% of neurons yielded phasic On-Off reaction to flashing stationary spots. Habituation to repeated stimulation was a common feature and occured in 50% of AMSS neurons. In 19% of neurons tested the discharge rate was not affected by saccadic eye movements, when the animal faced a patterned background. Among the remainder two types of saccade associated responses could be distinguished. Type I discharged prior to or simultaneously with the onset of saccades. This early response was usually associated with saccades of particular directions. Saccades in total darkness yielded weaker and less consistent responses. Type II discharged subsequent to the onset of the saccades after a latency of 40 msec (type IIa), 40–80 msec (type IIb) and 80 msec (type IIc). Responses of type IIa are probably consequences of the retinal effects of eye movements. The saccade associated responses of type Ia, IIb and IIc are tentatively interpreted as results of an eye movement-synchroneous subcortical input, which facilitates transmission in AMSS neurons. Presaccadic facilitation, which generates type Ia responses, may be functionally related to shifts of attention prior to eye movements. It is suggested that postsaccadic facilitation, which underlies the reactions of type IIb and IIc, may be a correlate of visual attention during the fixation period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236111
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  • 14
    Electronic Resource
    Electronic Resource
    The organization of projections from the cerebellar nuclei to the contralateral motor cortex in the cat (1974)
    Springer
    Experimental brain research 19 (1974), S. 36-60 
    Details
    ISSN: 1432-1106
    Keywords: Cerebellar nuclei ; Motor cortex ; Evoked potentials ; Topographical organization ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. A topographical study of cerebello-cortical relations was conducted in cats anesthetized with chloralose. The potentials evoked by punctate stimulation of the cerebellar nuclei were recorded at various sites in the contralateral motor cortex. A map of the cortical responses obtained by stimulating each of the cerebellar nuclei was established. For this purpose, the stimulation thresholds as well as the response amplitudes, polarity and latency were noted. 2. Local stimulation of each cerebellar nucleus evoked responses in particular regions of the contralateral motor cortex. When a stimulus was applied to the interpositus nucleus, short latency responses were recorded in the lateral part of the area 4. Dentate nucleus stimulation induced short latency responses in the medial part of area 4 and in area 6. Furthermore, late responses were also recorded laterally in area 4. 3. The interpositus nucleus was found to project to the portion of motor cortical area controlling the distal forelimb with only a fast conducting pathway. The fastigial nucleus seems to be connected with proximal and axial motor areas. The projection system of the dentate nucleus appears to have a temporal organization: a fast conducting pathway was found to project to the axial and proximal motor area while a slower one seems to transmit impulses to the motor area of the forelimb extremity. 4. The functional aspects suggested by the temporal organization of the cerebellocortical inputs and the distribution of each nucleus projections on the motor cortical areas are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233394
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  • 15
    Electronic Resource
    Electronic Resource
    Lack of fixed order of recruitment in cat motoneuron pools (1974)
    Springer
    Experimental brain research 20 (1974), S. 101-114 
    Details
    ISSN: 1432-1106
    Keywords: Size principle ; Motoneurons ; Cat ; Recruitment ; Neurophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Henneman et al. have shown that a wide variety of stimuli activate motoneurons in the order of their sizes, though some reversals occur. It is not clear which motoneurons should be included in the “pool” from which recruitment by size takes place. The “pool” may consist of 1. all the motoneurons to a given muscle 2. all the motoneurons in a given ventral root or 3. all the motoneurons activated by a given stimulus. We have examined recruitment in the pool of fibers to a given muscle. A variety of mechanical stimuli to cat's legs were used to elicit bursts of activity in gastrocnemius motor units. In 30% of pairs of units, one unit had a consistently lower threshold, i.e. it always began and ended a burst. In the other 70%, either unit could start or end a burst. For 48% of motor unit pairs recorded in either the medial or lateral gastrocnemius, each unit of the pair had runs of firing of at least 10 spikes while the other was totally inactive. By the same criterion, 23% of pairs of temporalis units showed differential activity. During spontaneous breathing there was no consistent recruitment order in 24% of pairs of units in throat respiratory muscles. These data indicate that reversals of recruitment order are relatively common for motoneurons innervating the same muscle. We discuss the possibility that size principle may hold for motoneurons in a single ventral rootlet whose somas are anatomical neighbors (even though they innervate different muscles), but not for motoneurons that are anatomically distant in the cord (even though they innervate the same muscle).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234005
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  • 16
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    Electronic Resource
    Effect of differential blocking of motor axons on antidromic activation of Renshaw cells in the cat (1974)
    Springer
    Experimental brain research 20 (1974), S. 135-143 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Renshaw cell ; Antidromic activation ; Differential blocking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Attempts were made to study differences in the relative effectiveness of different size ranges of motor axons to Renshaw cells by differential blocking of larger fibers of the gastrocnemius nerve in cats anesthetized with Nembutal. 1. Differential blocking of larger fibers in the nerve was successfully obtained by applying trapezoid wave current to the nerve. 2. It was shown that more than half (58.1%) of the Renshaw cells receive homogeneous inputs from a motor axon collaterals, 25.8% of the cell receive collateral inputs from a certain group of fibers, and 12.5% of the Renshaw cells were activated by “γ range” fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234008
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  • 17
    Electronic Resource
    Electronic Resource
    Reflexes in postganglionic fibres within skin and muscle nerves after mechanical non-noxious stimulation of skin (1974)
    Springer
    Experimental brain research 20 (1974), S. 115-123 
    Details
    ISSN: 1432-1106
    Keywords: Somato-sympathetic reflexes ; Postganglionic fibres to skin and muscle ; Natural stimulation of skin ; Hair-follicle receptors ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Somato-sympathetic reflexes in postganglionic neurones to hairy skin and to muscle produced by mechanical non-noxious stimulation of skin were studied in cats anesthetized with chloralose. Most of the postganglionic fibres investigated were spontaneously active and had presumably vasoconstrictor function. 2. In 60% of the cutaneous postganglionic neurones stimulation of hairs induced predominantly excitation. This excitation was mostly followed by a slight depression of the spontaneous activity. In 30% of the neurones the spontaneous activity was depressed or predominantly depressed by these stimuli. 3. In most muscle postganglionic neurones the spontaneous activity was depressed by stimulation of hairs. 4. In both types of neurones the reflexes were produced by activity in hair follicle receptors with Group II afferents. Hair follicle receptors with Group III afferents most probably also contributed to this effect. Except for a slight depression of the spontaneous activity in some cutaneous postganglionic neurones by slowly adapting receptors, mechanical stimulation of other types of receptors with Group II afferents had no effect on the postganglionic neurones. 5. Reflexes in postganglionic neurones could be elicited by stimulation of hairy skin all over the body surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234006
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  • 18
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    Electronic Resource
    Projections thalamiques des noyaux vestibulaires: Etude histologique chez le chat (1974)
    Springer
    Experimental brain research 20 (1974), S. 273-283 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nuclei ; Thalamic projections ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrolytic lesions were placed into the left vestibular nuclei of 22 adult cats. Silver impregnation for degenerated terminal fibres of serial sections revealed the existence of a relay of the corticopetal vestibular pathway in the contralateral thalamus. Its main afferent fibres originate in the superior and medial vestibular nuclei. By crosschecking the results it was possible to demarcate a focus of vestibular projections in the ventro-caudal part of the thalamus, situated between the centre median, the ventro-basal group and the caudal segment of the ventro-lateral nucleus. The direct ascending afferents of this focus are relatively few in number. The functional significance of this vestibular relay with regard to the proprioceptive influx passing through this region of the thalamus is open to discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238317
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  • 19
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    Electronic Resource
    Bilateral semicircular canal inputs to neurons in cat vestibular nuclei (1974)
    Springer
    Experimental brain research 20 (1974), S. 285-296 
    Details
    ISSN: 1432-1106
    Keywords: Ampullary nerve ; Cat ; EPSP ; IPSP ; Vestibular neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The six ampullary nerves in both labyrinths were separately stimulated by electric pulses in anesthetized cats. Resulting responses in neurons in the vestibular nuclei were recorded intracellularly. Almost all the vestibular neurons showed an EPSP in response to stimulation of the ipsilateral ampullary nerve. These neurons were subclassified as A-, L-, and P-neuron receiving specific projections from the anterior, lateral and posterior canal, respectively. Three fourths of the vestibular neurons recorded from received an IPSP in response to stimulation of the contralateral ampullary nerve. Plane-specific contralateral inhibition was found in most of vestibular neurons; i.e. A-, L-, and P-neuron received IPSP from the contralateral posterior, lateral, and anterior ampullary nerve, respectively. Approximately two thirds of vestibular neurons exhibiting the plane-specific inhibition were recorded in the medial vestibular nucleus. A collision test of impulses in primary afferent fibers were performed during recording of ipsilateral EPSPs produced by strong stimulation of more than one ampullary nerve. No positive evidence was provided for the existence of neural convergence on single vestibular neurons from different ampullary nerves on the same side. It is suggested that the plane-specific contralateral inhibition increase the sensitivity of vestibular neurons during head rotation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238318
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  • 20
    Electronic Resource
    Electronic Resource
    Responses of cat vestibular neurons to sinusoidal roll tilt (1974)
    Springer
    Experimental brain research 20 (1974), S. 347-362 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nuclei ; Tilt response ; Sinusoid ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular recordings were made in the lateral and inferior vestibular nuclei of decerebrate, unanesthetized cats. The firing patterns of single units were studied using small amplitude sinusoidal roll tilts of from 0.01 Hz to 1.0 Hz. Three-fourths of the tilt-sensitive units showed greater modulation of their firing rates as the frequency of the sinusoidal tilt was increased. The responses of cells in both nuclei were similar. These responses were virtually unchanged in cats with chronically plugged semicircular canals, indicating a probable otolith origin for the dynamics of the tilt response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237380
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  • 21
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    Electronic Resource
    Somatosensory cortical involvement in responses to noxious stimulation in the cat (1974)
    Springer
    Experimental brain research 20 (1974), S. 363-374 
    Details
    ISSN: 1432-1106
    Keywords: Pain ; Somatosensation ; Cerebral cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The experiment examines the role of the cerebral cortex in regulating responses to noxious stimulation by studying the effects of cortical ablations in cats on escape from electric shock applied to the foot pads. The latency of escape as a function of shock intensity was measured before and after bilateral ablations of various portions of the cat's somatosensory cerebral cortex. Ablations of the second somatosensory cerebral cortex significantly increased the escape response threshold. If the sulci bordering this region were included in the ablation, the threshold increase was greater and longer-lasting. Ablations of the primary somatosensory cortex increased latencies at most intensities of electric shock, but did not change the response thresholds. Ablations of both primary and second somatosensory cortex increased response thresholds and response latencies. None of these ablations altered the responses, however, if the cat had been overtrained for six to seven months prior to surgery. The results suggest that the second somatosensory region and the sulci bordering the second somatosensory region in the cat cerebral cortex are involved in responses to noxious stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237381
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  • 22
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    Electronic Resource
    An intracellular study of neuronal organization in the visual cortex (1974)
    Springer
    Experimental brain research 21 (1974), S. 45-66 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Efferent cells ; Non-efferent cells ; Synaptic connection ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal connections in the visual cortex of cat (areas 17 and 18) were studied with intracellular recording and electrical stimulation techniques under Nembutal anaesthesia. Four types of axonal projection were seen; 1. association efferent cells projecting to adjacent cerebral cortex on the ipsilateral side, 2. commissural efferent cells to visual cortex on the contralateral side, 3. corticofugal efferent cells to the ipsilateral lateral geniculate body and superior colliculus, and 4. non-efferent cells whose projection is confined within the visual cortex. Both association and commissural efferent cells were located in layer III, corticofugal efferent cells in layer V and non-efferent cells in layers II–VI. Upon these cells two types of synaptic actions were exerted by the specific visual afferents that originate from the lateral geniculate body; 1. type I, monosynaptic excitation plus disynaptic inhibition and 2. type II, disynaptic excitation plus trisynaptic inhibition. Type I effects were found in layers III–V, and type II in layers II and VI. In the border region between areas 17 and 18 monosynaptic excitation and disynaptic inhibition were produced also by the commissural efferents originating from the contralateral visual cortex. On the basis of these results, a possible neuronal circuitry in the visual cortex is postulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234257
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  • 23
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    Electronic Resource
    The lateral reticular nucleus in the cat III. Organization of component activated from ipsilateral forelimb tract (1974)
    Springer
    Experimental brain research 21 (1974), S. 501-513 
    Details
    ISSN: 1432-1106
    Keywords: Lateral reticular nucleus ; Spinoreticular tract ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The activation of neurones in the mLRN (major portion of lateral reticular nucleus comprising its parvi- and magnocellular parts) by two spinal tracts ascending through the ventral part of the lateral funiculus has been studied by recording from 277 neurones of which 187 could be antidromically activated by stimulation of the cerebellar surface. Forty-eight % of the neurones were activated by the bVFRT and described in a previous paper (Clendenin et al., 1975b) and 12% were activated by a previously unknown tract denoted the ipsilateral forelimb (iF) tract and described in the present paper. 2. The iF-tract is activated by stimulation of nerves in the ipsilateral forelimb only. The response consists of a train of impulses with a high initial frequency and an almost constant latency. Cutaneous afferents and high threshold muscle afferents contribute to the excitation which is mediated by interneurones. 3. The responses to stimulation of peripheral receptors were weak and difficult to classify. 4. The iF-tract activates neurones in the dorsolateral portion of the magnocellular part of the mLRN which projects to the ipsilateral pars intermedia of the anterior lobe and the ipsilateral paramedian lobule. 5. The possible information carried by the iF-tract is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237168
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  • 24
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    Electronic Resource
    On the origin of the corticotectal projections in the cat (1974)
    Springer
    Experimental brain research 21 (1974), S. 433-439 
    Details
    ISSN: 1432-1106
    Keywords: Superior colliculus ; Visual cortex ; Layer V-pyramids ; Clare Bishop area ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stereotaxic injection of horseradish peroxidase into the superior colliculus produced retrograde labelling of layer V pyramides in the Clare Bishop area and the lateral bank of the suprasylvian sulcus, in area 17,18 and 19. Single labelled cells were also found scattered in the splenial, the suprasplenial, the lateral and the suprasylvian gyri. In the cruciate sulcus no labelled cells were observed. Autoradiographically, the lateral bank of the suprasylvian sulcus was also shown to give rise to fibres to the superior colliculus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237905
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  • 25
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    Electronic Resource
    The lateral reticular nucleus in the cat II. Organization of component activated from bilateral ventral flexor reflex tract (bVFRT) (1974)
    Springer
    Experimental brain research 21 (1974), S. 487-500 
    Details
    ISSN: 1432-1106
    Keywords: Lateral reticular nucleus ; Bilateral ventral flexor reflex tract (bVFRT) ; Spino-reticulo-cerebellar path ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Neurones in the lateral reticular nucleus (LRN) activated by the bilateral ventral flexor reflex tract (bVFRT-LRN neurones) were identified by their responses to stimulation of fibres descending in the contralateral ventral quadrant of the spinal cord which activate the bVFRT neurones monosynaptically. 2. Eighty-eight of the 134 bVFRT-LRN neurones encountered could be antidromically activated at a low stimulus strength from small areas of the cerebellar surface assumed to represent cortical termination points. 3. The bVFRT-LRN neurones occurred throughout the parvi- and magnocellular parts of the LRN and terminated bilaterally in the anterior lobe and sparsely in the ipsilateral paramedian lobule and in the pyramis. 4. The responses evoked in the bVFRT-LRN neurones on stimulation of the contralateral ventral quadrant at C5 and L1 made it possible to estimate the approximate spinal level from which the bVFRT fibres originated. On this basis the bVFRT-LRN neurones were divided into cervical, thoracic, and lumbar groups receiving bVFRT afferents from mainly one spinal level and a convergence group receiving bVFRT afferents from several levels. 5. The different bVFRT-LRN groups received excitation from different combinations of nerves in the four limbs. 6. The cervical, thoracic and lumbar groups of the bVFRT-LRN neurones occurred in successively more ventrolateral portions of the LRN. 7. The cervical, thoracic and lumbar groups of the bVFRT-LRN neurones terminated in successively more rostral areas of the anterior lobe. 8. The organization of the bVFRT-LRN path is compared with that of the ventral and rostral spinocerebellar tracts. The possible function of the bVFRT-LRN path is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237167
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  • 26
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    Electronic Resource
    Effets de la stimulation des fibres et des mécanorécepteurs splanchniques sur l'activité unitaire du cortex somesthésique (1974)
    Springer
    Pflügers Archiv 348 (1974), S. 127-137 
    Details
    ISSN: 1432-2013
    Keywords: Splanchnic Afferents ; G.I. and Peritoneal Receptors ; Cortical Projections ; Microelectrode Technique ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The experiments were performed on cats anesthetized with chloralose or Nembutal. The unitary activity of cortical neurons was recorded in the SI and SII areas by means of extracellular glass microelectrodes. The neurons showed frequently a spontaneous discharge (irregular or regular tonic discharge bursts of spikes). The electrical stimulation of contralateral splanchnic nerves produced different effects on a great number of the neurons: 1. early short activation, 2. late activation, 3. early and late complex activation, 4. partial or total inhibition of the spontaneous activity. These effects were obtained in the different cortical layers. Similar results have been observed by mechanical stimulation of the splanchnic receptors located in the gastro-intestinal tract and in the peritoneum. However in this case, the duration and the amplitude of inhibition and activation were generally weaker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586475
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  • 27
    Electronic Resource
    Electronic Resource
    Junctions in the central nervous system of the cat (1974)
    Springer
    Cell & tissue research 148 (1974), S. 577-586 
    Details
    ISSN: 1432-0878
    Keywords: Node of Ranvier ; Axonal-glial junctions ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paranodal zone of myelinated nerve fibers from the CNS of cats has been studied by means of the lanthanum technique and after freeze-etching. Special interest was given to the axonal-glial zones of contact in this region. Examination of the membranes of the paranodal pockets and the axolemma revealed that the membrane thickenings which occur between the adjacent membranes actually consist of bands. The bands show a specific pattern of diagonal running subunits 10 nm apart. These substructures of the axonal side of the membrane contacts protrude outwards, i.e. towards the glial membrane, where they fit into depressions on the glial membrane surface. This arrangement in form of a “zip-fastener” makes the whole structure very flexible. The subdivision of the bands was identified with both techniques. The different membrane aspects obtained by the freeze-etching technique are discussed in respect to the splitting theory, and a hypothetical model of this membrane specialization is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221941
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  • 28
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    Electronic Resource
    Electron microscopic investigation of synaptic organization of the trochlear nucleus in cat (1974)
    Springer
    Cell & tissue research 150 (1974), S. 409-423 
    Details
    ISSN: 1432-0878
    Keywords: Synaptic organization ; Trochlear nucleus ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two distinct types of neuron in the cat trochlear nucleus (one large, one small) are described, the α- and γ-motoneurons, respectively. Four types of terminals are observed which establish axo-dendritic synapses. Two of them (Types I and II) perform axo-somatic synapses as well. Terminals en passant (Types I and II) are predominant. The Type I terminal is long and slender with a characteristic distribution of the axoplasmic organelles and the unique feature of a relative narrowing of the synaptic cleft as compared to the width of the neighboring extracellular space. Its vesicle population is pleomorphic and a conspicuous glial barrier surrounds the synaptic zones. The Type II terminal differs slightly from Type I, revealing a wider synaptic cleft and lacking a characteristic distribution of the axoplasmic organelles. The type III terminal is rarely observed performing axo-somatic synapses, but is a common finding in the neuropil. Post-junctional dense bodies are often present in its axodendritic synapses. The Type IV nerve terminal performs axo-dendritic synapses and is characterized by a rich content of large granulated vesicles. Axo-axonal synapses are observed only very rarely. The synaptic organization of the feline trochlear nucleus is compared with the synaptic morphology of the oculomotor nuclei of inframammalian species (Waxman and Pappas, 1971). In addition to certain similarities (e.g., richness of synapses en passant), significant differences are encountered: the present study provides no morphological evidence for electrotonic transmission in the trochlear nucleus of cat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220147
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  • 29
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    Electronic Resource
    Some observations on the ultrastructure of the central amygdaloid nucleus in the cat (1974)
    Springer
    Cell & tissue research 151 (1974), S. 489-498 
    Details
    ISSN: 1432-0878
    Keywords: Limbic system ; Cat ; Amygdaloid body ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study was undertaken to re-examine the central nucleus of the cat in Nissl stained sections, to describe its fine structural characteristics, and to compare the lateral subdivision of this nucleus with the putamen. In Nissl preparations, it was observed that the lateral subdivision of the central nucleus contains a fairly homogeneous population of small cells while the putamen contains both small and large cells. It is the presence of a few large cells at the lateral periphery of the lateral part of the central nucleus that makes the boundary between the two nuclei indistinct. Examination of the fine structure of the medial and lateral subdivisions of the central nucleus revealed the presence of many boutons containing flattened vesicles and fewer with spheroid vesicles. In contrast, most of the boutons in the putamen have spheroid vesicles. It is concluded that the lateral subdivision of the central nucleus may be distinguished from the putamen, except at its most lateral border, by its homogeneous population of small cells and its many boutons containing flattened vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222994
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  • 30
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    Electronic Resource
    Junctions in the central nervous system of the cat (1974)
    Springer
    Cell & tissue research 149 (1974), S. 121-135 
    Details
    ISSN: 1432-0878
    Keywords: Astrocytic membranes ; Cat ; Orthogonal particle-complexes ; Freeze-etching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fixed and unfixed astrocytic membranes from the CNS of the cat were studied by means of the freeze-etching technique. A variable number of gap junctions was detected in astrocytic membranes. They are characterized by the well known hexagonal composition of their subunits. Besides this type of highly ordered membrane-bound particles, a second one was found. It is composed of four single particles (diameter 5 nm) which form an orthogonal subunit with a side length of about 10 nm. These membrane-associated orthogonal particle complexes (MOPC) could be observed in different stages of aggregation and expansion. They reveal an accumulation in membranes of the marginal glia layers and in the perivascular astrocytic end-feet. Unfixed, glycerol treated membranes, however, do not show these structures. After glycerol treatment of the unfixed membranes by immersion, the MOPC disintegrate to single particles which form clusters of various extension. The clustering phenomenon is dependent on the length of the time of exposure to glycerol. Shortening of the glycerol treatment by intravasal perfusion of the cryoprotectant agent causes an decrease of the clusters. Fragments and transient forms of the MOPC become visible. By variation of different physico-chemical parameters of the washing solution a similar effect on the MOPC was not achieved. The discussion deals with probable functional aspects of the MOPC. They are considered to act as membrane-bound functional multienzyme complexes which a) might play a role in mediating transmembrane passage of metabolites, or b) are essential for CSF control mechanisms, or c) have a functional relation to the nexus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209055
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  • 31
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    Electronic Resource
    Nerve endings in the arteria centralis retinae (1974)
    Springer
    Cell & tissue research 150 (1974), S. 143-145 
    Details
    ISSN: 1432-0878
    Keywords: Arteria centralis retinae ; Cat ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Terminal axons emerging from the inner plexiform layer of the cat retina reach the wall of the arteria centralis retinae, as revealed by electron microscopy. Numerous unusually large dense core vesicles (about 1000 Å in diameter), of different electron densities, occur in the varicosities of these axons. These observations may be compatible with the idea of an innervation of the central artery of the retina which is non-autonomic, possibly intrinsic in nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220387
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  • 32
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    Electronic Resource
    Junctions in the central nervous system of the cat (1974)
    Springer
    Cell & tissue research 148 (1974), S. 565-576 
    Details
    ISSN: 1432-0878
    Keywords: Central myelin ; Junctions ; Cat ; Freeze-etching ; Lanthanum impregnation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In male and female cats central myelin was studied using the freeze-etching technique, and after impregnation with lanthanum as a tracer. The freeze-fractured and etched faces of the myelin reveal membrane formations which in many respects resemble tight junctions. The formations consist of parallel rows of particles on one half of the membranes matched by corresponding furrows on the other membrane half. These structures occur across the width of the myelin sheath and are most common in that part of the myelin underlying the external cytoplasmic loop. They are interpreted as correlates of the radial component of the i-line which occurs in cross-sections of central myelin after potassium permanganate staining. In the paranodal zone the lanthanum-impregnated myelin displays punctate fusions between the outer leaflets of the oligodendrocytic membranes. These findings strongly suggest that tight junctions are a common feature in the central myelin. The arrangement of the membrane fusion in relation to the elements of the lamellar complex and their functional significance is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221940
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  • 33
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    Hypothalamic projections to the amygdala in the cat (1974)
    Springer
    Cell & tissue research 151 (1974), S. 499-508 
    Details
    ISSN: 1432-0878
    Keywords: Limbic system ; Cat ; Amygdaloid body ; Hypothalamus ; Stereotaxic lesions ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to determine the origin of the hypothalamo-amygdaloid connections in the cat, small lesions were placed at various rostro-caudal levels of the hypothalamus. The animals were sacrificed after a period of 4, 8 or 11 days and the brains stained with the Nauta (1957), Fink and Heimer (1967) or Wiitanen (1969) method for the demonstration of degenerating axons and their terminals. It was observed that the anterior hypothalamic nucleus sends a small projection to the medial subdivision of the central nucleus and to the basal and lateral nuclei of the amygdala. The lateral preoptic area sends a larger projection to the anterior amygdaloid area, both subdivisions of the central and basal nuclei, and to the lateral and medial nuclei. No degeneration was observed in the amygdala following lesions in the medial preoptic area, the ventromedial nucleus or the lateral hypothalamic area caudal to the anterior hypothalamic area. In a series of animals with lateral preoptic lesions, the site of termination of degenerating boutons on neurons of the amygdaloid nuclei was determined and the course of the degenerative process followed over a period ranging from 2 to 15 days. Many of the boutons, especially in the earlier stages of degeneration, appeared to be of the B3 type, containing flattened vesicles and forming symmetrical synaptic contacts with dendrites or somata. With longer post-operative survival times, however, they became increasingly electron dense and shrunken, so that the bouton type could not be determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222995
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  • 34
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    Electronic Resource
    Announcement (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 315-316 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080216
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  • 35
    Electronic Resource
    Electronic Resource
    Irreducible tensor operator methods in intermediate-field coupling (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 347-362 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The algebra of irreducible tensor operators is developed in the intermediate-field coupling case. The Wigner-Eckart theorem is formulated for a simple irreducible tensor operator as well as for the Kronecker and scalar products of these operators. The expressions required for the calculation of Coulomb repulsion, crystal field splitting, spin-orbit interaction, and Zeeman effect are given in detail. Recent applications to various problems in spectroscopy and magnetism of transition metal compounds are referred to.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080304
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  • 36
    Electronic Resource
    Electronic Resource
    SCF equations for pure spin states with many-particle interactions (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 539-546 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: SCF equations for any pure spin state are given for a spin-free system with many-particle interactions. The equations are very simple and explicit. Due to the use of different antisymmetric requirement our equations are different from some of the other methods. In our method, the abstract group theory formalism is converted into some explicit and straightforward equations which makes the many-particle interaction problem easier to handle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080405
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  • 37
    Electronic Resource
    Electronic Resource
    Unified treatment of two-electron integrals. II. One-center, electron repulsion, spin-spin and spin-orbit integrals containing rij (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 635-642 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: General formulas are obtained for evaluating a basic type of one-center two-electron integral which arises in the computation of expectation values of spin-spin and spin-orbit operators over explicitly correlated wave functions. The correlation terms are assumed to be in the form of products of Slater functions and powers (not necessarily integer) of the interelectronic coordinate rij.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080502
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  • 38
    Electronic Resource
    Electronic Resource
    Perturbative ab initio calculations of intermolecular energies. II. The He ··· He problem (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 17-28 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ground state energy of the He2 system is calculated according to the techniques described in Paper I around the van der Waals equilibrium, without assuming the constancy of the intraatomic correlation energies. The second-order results do not present an attractive region; the S2 decrease of the intraatomic correlation correlation corrections is larger than the attractive interatomic correlation corrections. The further orders reverse progressively the situation and finally give a qualitatively correct potential curve after the fifth order. Reaching almost exact solutions in the considered basis, one can demonstrate that the intermolecular calculation of the system A + B in the union of the basis for A and B involves an energy decrease which simply represents the effect of the extension of the basis set; and that a proper intermolecular calculation must compare the A + B energy with the A and B energies calculated in conveniently extended basis sets including the vacant MO's of the partner.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080103
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  • 39
    Electronic Resource
    Electronic Resource
    More on molecular electronic structure of metal phthalocyanines (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 79-82 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular orbitals of some of the 3d-transition metal phthalocyanines have been calculated. π-Electron charge densities over the atomic sites and the optical properties of the metal phthalocyanines have been calculated. The effect of the introduction of different metal atoms in the centre of the organic ring on the physical properties of the metal phthalocyanines has been discussed.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080108
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  • 40
    Electronic Resource
    Electronic Resource
    Convergence problems in the solution of SCF equations (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 107-117 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some problems connected with the convergence of iterative solutions of the Hartree-Fock equations for the open shell systems are discussed. The nonuniqueness of the Hartree-Fock operator form is used.The method of iterating by the operator's power is developed for obtaining solutions of the Hartree-Fock equations. Some particular results for the molecules Li2+, Li2- are presented.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080112
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  • 41
    Electronic Resource
    Electronic Resource
    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080201
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  • 42
    Electronic Resource
    Electronic Resource
    Correlation effects in the low-lying excited states of the PPP models of alternant hydrocarbons. I. Qualitative rules for the effect of limited configuration interaction (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 951-970 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple rules for an estimate of the correlation effects in the low-lying states of alternant hydrocarbons, as described by the Pariser-Parr-Pople Hamiltonian, are formulated. These rules are based on the alternancy and spin symmetry classification of states in both strongly and weakly correlated limits and on the valence bond characteristics of those states in the fully correlated limit. It is shown that the largest effect of the electron correlation will be found for the singlet “minus” states (using Pariser's classification of the alternancy symmetry species), a smaller effect for the triplet “plus” states, and a much smaller effect for the remaining states. These rules are exemplified by limited CI calculations including all monoexcited and all mono- and bi-excited configurations, respectively, for a number of π-electronic systems. In view of these rules the success of the PPP model in the monoexcited CI approximation may be understood.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080610
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  • 43
    Electronic Resource
    Electronic Resource
    Potential energy integrals in semiempirical MO methods (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 263-266 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The two-center core-electron attraction integral VAB in zero-differential overlap semiempirical MO methods is examined. It is concluded that core-valence orthogonality and valence symmetrical orthogonalization effects must be considered, and that these effects provide justification for the CNDO/2 approximation VAB = ZBγAB.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080213
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  • 44
    Electronic Resource
    Electronic Resource
    Static and dynamic first- and second-order properties by variational wave functions (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 293-314 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The problem of the evaluation of first- and second-order energies by the use of arbitrary variational wave functions is examined in detail for time-independent perturbations as well as for time-dependent perturbations. By using a compact formalism the general formulae to be used for the case of a fully optimized set of variational parameters are readily obtained and the most prominent features are examined. The generality of the approach is tested by showing how some widely used methods are obtained by using particular types of variational wave functions. The case of incompletely optimized sets of variational parameters is examined examined extensively and several approaches at different levels of approximation are proposed. Emphasis is put upon the importance of considering, in the calculation of higher-order energies, the variational parameters which may be of negligible importance, and thus often neglected, in the absence of perturbations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080215
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  • 45
    Electronic Resource
    Electronic Resource
    Spin projected EHF method: Calculations for a four-electron model system (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 363-372 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The spin projected extended Hartree-Fock equations for successive optimization of the orbitals are derived for the four-electron case and applied to butadiene in the PPP approximation. The method shows an excellent convergence and gives 91.4% of the correlation energy for the given model-Hamiltonian.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080305
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  • 46
    Electronic Resource
    Electronic Resource
    Molecules-in-molecules calculations with fixed resonance integrals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 427-433 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A simple equation for the evaluation of resonance integrals from overlap integrals and ionization potentials of the molecular fragments is suggested for molecules-in-molecules π electron calculations. The singlet π → π* transition energies of some benzene derivatives containing donor substituents were calculated. The best results were obtained if in the expression of the resonance integral the first experimental ionization potential of the methyl derivative of the donor groups is used.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080309
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  • 47
    Electronic Resource
    Electronic Resource
    Approximate valence-shell electron unrestricted Hartree-Fock calculations with orthogonalized atomic orbitals: Proton hyperfine splittings in benzyl and related radicalsPaper presented at the First International Congress of Quantum Chemistry, Menton, France, July 4-10, 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 451-465 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A modified INDO procedure has been used to calculate the proton hyperfine splittings in benzyl and the isoelectronic anilino, phenoxy and 2-azabenzyl as well as 2- and 3-thenyl radicals. The present procedure differentiates between s-, p- and d-orbitals on an atom in estimating various integrals involving them, satisfies the rotational invariance requirements and employs an orthogonalized basis set of atomic orbitals for obtaining core-Hamiltonian matrix elements. The calculations based on using the exponents which depend only on the type of orbital and the nature of atom fail to provide correct relative order of ortho and para proton splittings in benzyl as well as anilino, phenoxy and 2-azabenzyl radicals. On the other hand, use of the exponents which are modified according to the charge densities in various orbitals leads to a high absolute value for para proton splitting compared to that for ortho proton splitting which in case of all these radicals is in agreement with experiment. A spin density calculation on benzyl, anilino and phenoxy radicals considering the variation of one-center one-electron and one-center two-electron integrals for different protons with their charges is found to yield further improvement in the relative order of ortho and para proton splittings in all these radicals. In 2- and 3-thenyl radicals the role of 3d-orbitals on sulfur has also been examined. To our knowledge, no unrestricted INDO calculations including 3d-orbitals on sulfur have been reported in the literature so far.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080311
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  • 48
    Electronic Resource
    Electronic Resource
    The loge theory as a starting point for variational calculations. I. General formalismPresented at the 7th Meeting of the International Academy of Molecular Science, July 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 499-522 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that any expectation value of any observable associated with a molecule is the sum of loge contributions and of loge pair contributions. This result provides a rigorous theoretical basis for the study of additive properties of molecules.It is demonstrated that molecular wave functions (exact or approximate) can be expressed as a sum of functions corresponding to the various electronic events. Furthermore any of these event functions can be expressed in terms of correlated loge functions. This expression suggests many kinds of variational procedures of calculating wave functions (known methods and new ones).The case in which noncorrelated completely localized loge functions are used is discussed. If continuous functions are used the variational equation reduces to a sum of independent variational equations, each one corresponding to a particular electronic event. This is not so when discontinuous functions are used or when a delocalized function is added to replace the correlation interloge function.The noncorrelated completely localized loge model is analyzed in more detail. It is seen that local spin operators can be introduced and that each event density operator is the product of the loge density operators. Therefore that model is an independent loge model. The corresponding generalized self-consistent field equations are derived. This treatment helps us to understand how a localized state of a molecule can produce an ion containing a delocalized region, a phenomenon which is sometimes at the origin of some misunderstanding in photoelectron spectroscopy. Finally it is seen how virtual loge functions can be introduced to describe excited states.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080403
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  • 49
    Electronic Resource
    Electronic Resource
    Matrix elements in configuration interaction calculations (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 605-617 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is proposed for the calculation of matrix elements among various states of atoms. A set of tensor operators is the only entity in the formalism, and all formulas involve merely the vacuum expectation values of these tensor operators and the recoupling transformation coefficients. Some numerical examples are given for the Coulomb interaction matrix elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080410
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  • 50
    Electronic Resource
    Electronic Resource
    Hybridization by the maximum overlap methodSupported in part by the National Science Foundation (Grant GP-31373 and 14012X). (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 643-676 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A brief survey of the maximum overlap method is presented and some computational aspects of the approach are discussed. The hybrid compositions and bond overlaps are reported for some thirty small ring compounds and a list of characteristic hybrids for various structural environments is given. The table of characteristic hybrids is extended to acyclic hydrocarbons and the transferability of the maximum overlap hybrids is demonstrated. Those aspects of the method which depend on geometrical properties of molecules have been considered in some details and the discussion is extended to some structural features of cyclic systems. In particular the asymmetry of bonds of spiro carbon atom is examined and rationalization of puckering of large macrocyclic systems is presented. In the summary it is pointed to the method and its potential to discuss structural aspects of molecules at the particular level of accuracy expected to be of great use in organic and physical organic chemistry. Further development and improvement of the method is mentioned, but already in the present form it can produce hybrids which may constitute a useful basis for other more ambitious semiempirical calculations.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080503
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  • 51
    Electronic Resource
    Electronic Resource
    Eigenspace manipulation in SCF theory: General formalism (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 423-426 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A general formalism in order to deal with SCF eigenspace manipulation is developed. It can be shown that the initial generalized secular equation splits into a set of secular equations, each of which in turn can modify independently any predetermined subset of the SCF manifold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080308
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  • 52
    Electronic Resource
    Electronic Resource
    An improved Hellmann-type pseudopotential for atoms and molecules (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 435-450 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concept of pseudopotentials offers much attractiveness for the quantum mechanical evaluation of the physical properties of atoms and molecules. The ideas of Hellmann, in which the repulsive and fermion character of inner electrons can be mimicked by an experimentally fitted, exponentially damped potential term, are especially attractive. Unfortunately, it is found that such a simple expression can only be used in a very limited number of cases, such as for the alkali metals, and even then fails for the simple case of lithium.The present study shows that the Hellmann idea can readily be extended by including a second “shielded potential” term evaluated from tabulated previous Hartree-Fock calculations. The new expression for the model pseudopotential is both simple and effective. With it, the inner potential of any of the alkali metal atoms, including lithium, can be represented so that calculation of the molecular properties of the metal dimers can be accomplished. Calculations for Li2, Na2, and K2 show the binding energies and equilibrium interatomic distances to be quite well given, in agreement with both chemical experience and spectroscopic evidence.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080310
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  • 53
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    Electronic Resource
    An investigation into the use of expansion methods in the calculation of chemical shifts and diamagnetic susceptibilities (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 745-754 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shift and the diamagnetic susceptibility of the hydrogenic atom with magnetic dipole and origin of the external magnetic field vector potential noncoincident with the hydrogenic nucleus have been calculated from perturbation theory using a set of expansion functions whose radial parts are single exponent associated Laguerre functions. In contrast to hydrogenic expansion functions these functions give rapid convergence to the exact values of the second-order energy summations when centred at the hydrogenic nucleus. The rate of convergence is fairly insensitive to the choice of expansion function exponent.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080509
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  • 54
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    Calculation of the magneto-optical activity of the hydrogen moleculeResearch supported by the National Science Foundation and the Danish Science Foundation. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 789-797 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We calculated the Verdet constant of the hydrogen molecule. We found that the angle of rotation may be represented by φ0 = A0Hv2/(v02 - v2)2 where A0 is 3.23 × 10-33 microminutes sec2 per oersted-cm-atmosphere. This is in agreement with the experimental observations where φ0 is given by the same frequency dependence with the constant A0 × 2.72 = 10-33 in terms of the same units.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080514
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  • 55
    Electronic Resource
    Electronic Resource
    Spin-Projected extended Hartree-Fock equations. II. Odd-electron systems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 893-899 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The spin-projected extended Hartree-Fock equations discussed in Part I for an even number of electrons are given here for the odd-electron case.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080605
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  • 56
    Electronic Resource
    Electronic Resource
    Matrix elements in all valence electron models (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 925-940 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Model Hamiltonians for all valence electron calculations are examined with regard to the possibility of obtaining consistent sets of matrix elements for the description of electromagnetic processes such as photon absorption, optical activity, and magneto-optical activity. Linear and angular momentum and position operator matrix elements are related to Hamiltonian matrix elements through symmetry relations and equations of motions. The possibility of elimination of empirical interatomic matrix elements is studied.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080608
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  • 57
    Electronic Resource
    Electronic Resource
    Symmetry in the Heitler-London method. I. The connection of the molecular point group with its electron permutation group in the Heitler-London method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 163-169 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The connection between the electron coordinates permutation group and the molecular point group is exhibited in the framework of the Heitler-London method. It is shown that the initial wave function of a molecule in the Heitler-London method can be written in such a form, that the effect of the point group operations upon this function corresponds to the permutation of the sets of electron coordinates of the ions and the subsequent multiplication of this function by some constants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080203
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  • 58
    Electronic Resource
    Electronic Resource
    Integral transform functions and separable potentials (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 209-221 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: General forms for asymptotic wave functions are derived from properties of the relevant Green's function. The use of separable potentials constructed from the asymptotic functions is described and the relation with integral transform functions is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080208
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  • 59
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    A comparative calculation on excited state energies of some conjugated hydrocarbons (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 247-253 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The energies of the single-configuration lowest π - π* singlet and triplet states of some conjugated hydrocarbons have been calculated by the MC-SCF method using the conjugate-gradient technique of minimisation. The results are compared with those calculated by other methods currently in use, like (a) single-configuration calculation with VN-1 potential for virtual orbitals; (b) CI calculation involving singly excited states; and (c) TDHF method. It has been concluded that the results for the MC-SCF method are very good, considering that only a single open-shell configuration is involved.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080211
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  • 60
    Electronic Resource
    Electronic Resource
    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080301
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    Validity of the three-center, four-electron model for stability of rare gas halides on the basis of exchange perturbation theory (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 335-345 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In a previous publication [1] we analyzed the stability of rare gas halides on the basis of exchange perturbation theory of the Rayleigh-Schrödinger type, using a three-center, four-electron model. In this paper, the analysis is extended to a (n + 1)-center, (n + 2)-electron model for rare gas halides of composition RXn, where R is the rare gas atom and X the halogen atom, in order to investigate the validity of the three-center, four-electron model. The compounds analyzed are XeFn, XeCln, KrFn and KrCln with n = 3 and 4, in different geometric configurations and for different states of total spin S. As before, we use exchange perturbation theory in first and second orders. The results are in good agreement with those obtained in the previous analysis and with experiments. Specifically, it is found that chlorides of rare gas atoms are not stable, that XeF4 has the square-planar configuration and that trifluorides cannot exist. The possible existence of KrF4 is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080303
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  • 62
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    Generalized open shell SCF theory (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 373-394 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A generalized form of the coupling operator technique in SCF theory has been developed. In the formalism presented here, the monoconfigurational problem may be treated as a particular case of the multiconfigurational framework. The matrix form of the operators has been analyzed; in the LCAO context a structure has been found which is very adequate for computational purposes.Some examples are also presented which show the usefulness of the theory, emphasising the CNDO and INDO approximations. Within the application of the method to ab initio calculations, some He and second row atoms states have been studied. The He first excited singlet is also studied, the result of the analysis of such a problem being that the nonorthogonality between the singlet functions of the fundamental and of the first excited states play a primordial role in the efficiency of the method.In no case have the calculation problems, appearing in the application of the theory, been of a more difficult nature than those normally found in the application of the formalism for closed shells.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080306
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  • 63
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    Interaction of two H2 molecules: Comparative study of various perturbation procedures (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 467-489 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A variational calculation of the interaction between two H2 molecules using minimal basis set of 1s functions is performed to check the efficiency of various versions of the perturbation theory for intermolecular interactions. The matrix procedure starting with the zero-order Hamiltonian which is symmetric with respect to intermolecular electron permutations shows better convergence than the procedures using nonsymmetric zero approximations. This conclusion follows from the calculations of ground state and four lowest excited states for three geometric configurations of the H4 system. The behaviour of the potential curves is interpreted in terms of symmetric perturbation theory. The various contributions to the interaction energy are considered in detail. The importance of charge transfer states for the description of the intermediate range of intermolecular separations is specially emphasized.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080312
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  • 64
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    A study of the symmetry dilemma: Second-order transitions (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 559-564 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Transitions from symmetry-adapted to symmetry-broken solutions of variational problems are classified according to the nature of the discontinuity involved. Two systems in which a second-order transition occurs are studied.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080407
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  • 65
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    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080501
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  • 66
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    The hammerstein integral equation: a general technique for constructing a rapidly convergent padé-type approximation to the logarithmic derivative (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 693-706 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radial one-electron Schrödinger equation can be written as a nonlinear first-order differential equation by making a suitable logarithmic transformation. The resulting Riccati equation has the equivalent Hammerstein integral representation [1], \documentclass{article}\pagestyle{empty}\begin{document}$$ \beta (r) = \int_{r' = 0}^\infty P(r') N(r,r')dr' \quad 0\buildrel{〈}\over{=} r 〈 \infty $$\end{document} where the kernel, N(r, r′) is \documentclass{article}\pagestyle{empty}\begin{document}$$ N\left( {r,\,r\prime} \right) = H\left( {r,\,r\prime} \right)\exp \left\{ {\int_{\xi = r\prime}^r {R\left( \xi \right)\beta \left( \xi \right)d\xi } } \right\} $$\end{document} and H(r, r′) is the Heaviside unit step function. This kernel is a more general one than that developed in ref. [1]. Both kernels apply in cases where the Riccati equation corresponds to a Sturm-Liouville problem.It is shown that this integral equation can be integrated by parts so that, for any local potential, the integrand decreases as the cyclic folding procedure is applied. During this cyclic folding, the kernel generates an equation that contains only coefficients of β(r)0 and β(r)1. Consequently, after truncating at the end of the nth cycle, it is possible to write down a Padé-type approximation to the logarithmic derivative as a known function of the independent variable. All coefficients in this approximation can be evaluated as simple algebraic formulations of P(r), R(r), and integrals over P(r).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560080505
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  • 67
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    Symmetry in the Heitler-London method. II. The determination of the allowed molecular multiplets (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 171-177 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the framework of the Heitler-London method, a method for determining the allowed molecular multiplets is proposed. The method is based on the connection of the total molecular spin with the permutation symmetry of the coordinate wave function and on the isomorphism of the molecular point group with a certain subgroup of the electron permutation group. The method does not depend on the approximation in which the molecular ions are considered.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080204
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  • 68
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    Dual-basis orthonormality-constrained variation method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 765-775 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The method of orthonormality-constrained variation is extended using a dual-basis set instead of a single orthonormal basis. The complete and the partial variation methods are discussed and applied to electronic systems. It is found that the present formulation leads to the most general equation in the coupling operator method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080511
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    Method of complex molecular orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 799-816 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the spirit of Löwdin's extended HF scheme, an SCF method for the description of the molecular ground state, based on complex molecular orbitals, is developed. As a special case the method of parity mixing in orbitals is formulated. A calculational procedure for solving derived secular equations is described and numerical results, obtained in the minimal basis set, are reported for the N2 and CO molecule. Resulting ground state energies are close to the energies of the CI calculations with the same set of orbitals.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080515
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    Electronic correlation studies. II. Self-correlated field method. Application to ground state and first 1P, 3P excited states of two-electron atomic systemsAbstracted from part of a thesis submitted by R. Lissillour to the University of Rennes, 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 825-838 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An antisymmetric pair function can be built upon two kinds of monoelectronic functions, the former ones being correlated local functions and the second ones nonlocal functions taking external effects into account. This function, brought into the generalised product function procedure by means of the density matrix formulation, makes possible the study of correlation within N-electronic systems. The results of a first application of this method to the fundamental and to 1P and 3P excited states of two-electron systems are given.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/qua.560080602
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  • 71
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    Configuration interaction calculations on the nitrogen molecule (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 61-72 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A contracted Gaussian basis set capable of describing about 63% of the correlation energy of N2 has been used in a detailed configuration-interaction calculation. Second-order perturbation theory overestimated the correlation energy by 23-50% depending on how H0 was chosen. Pair-pair interaction affects the correlation energy by about 20% while quadruple excitations have an 8% effect.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080106
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    Matrix elements for spin-adapted configurations (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 83-89 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the turn-over rule which is used to simplify matrix elements between spin-projected Slater determinants may also be used to simplify formation of matrix elements between any orthonormal set of spin-coupled Slater determinants. The coefficients for the spin-coupling may then be chosen freely to reduce the number of important configurations in the secular equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080109
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    Application of the distinguishable electron method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 137-150 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to make a better assessment of the distinguishable electron method developed by Kirtman and co-workers, we have applied the method to some two-electron atoms and to H2 and LiH. Our results lend support to the contention held by Kirtman and co-workers that the distinguishable electron method is a practical way of calculating reasonably accurate physical properties.
    Additional Material: 10 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080114
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    Waller-Hartree spin-free method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 523-537 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper we show that with the equivalent transformation Pr = (-1)P(Pσ)-1 the spin function dependent methods such as Slater's method without group theory or Goddard's method with group theory differ only in different antisymmetric requirements from the present Waller-Hartree spin function free method. There exists a one-to-one correspondence between Slater's determinantal wave function and the Waller-Hartree double determinantal wave function. Explicit expressions for the S2 operator, Löwdin's spin projector, matric basis and several different forms of spin-projected functions are given for the Waller-Hartree formalism. The results are compared with other methods including those of Slater, Matsen, Gallup, Goddard and Segal. The differences are quite significant. New spin operators are worked out using creation-destruction operators. A knowledge of group theory is not required in this Waller-Hartree method. We have also shown that the Waller-Hartree method is more convenient than Slater's method with spin functions especially in the evaluation of the functional HΨ/Ψ. The advantages and disadvantages in the use of a linear combination of N! Hartree products and linear combinations of all possible double determinants are discussed. In addition, a formula for the calculation of the Sanibel coefficients C(S, M, i) is obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080404
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    Nonbonded interactions in membrane active cyclic biopolymers. I. Valinomycin-potassium ion complexThe results of this paper were presented in summarized form at the Edward U. Condon International Symposium on Atomic, Molecular and Solid State Theory and Quantum Biology at Sanibel Island, Florida, U.S.A., January 1973. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 565-583 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for quantitative comparison of various conformers of cyclic macromolecules in terms of nonbonded interaction energy terms is proposed. The first step in the procedure is an analytical evaluation of a set of Cartesian atomic coordinates consistent with the ring closure condition and prescribed values for internal parameters. A variant of the same technique enables different conformations of the macromolecule to be generated. Nonbonded interactions of the electrostatic, polarization and dispersion type and van der Waals repulsion are calculated using the generated coordinates, empirical bond polarizability data and results of simple molecular orbital calculations. An application of the proposed techniques to the closed symmetric conformation of valinomycin indicates that the macromolecule by itself is somewhat constrained in this state but that its affinity for a potassium ion is very strong - much stronger than the hydration energy of the latter.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080408
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    Intermediate problems for eigenvalues (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 623-625 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080412
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    Ab initio calculations on urea (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 857-892 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multiconfiguration wave functions constructed from contracted Gaussian-lobe functions have been found for the ground and valence-excited states of urea. ICSCF molecular orbitals of the excited states were used as the parent configurations for the CI calculations except for the 1A1(π → π*) state. The 1A1(π → π*) state used as its parent configuration an orthogonal linear combination of natural orbitals obtained from the second root of a three-configuration SCF calculation. The lowest excited states are predicted to be the n π → π* and π → π* triplet states. The lowest singlet state is predicted to be the n π → π* state with an energy in good agreement with the one known UV band at 7.2 eV. The π → π* singlet state is predicted to be about 1.9 eV higher, contrary to several previous assignments which assumed the lowest band was a π → π* amide resonance band. The predicted ionization energy of 9.0 eV makes this and higher states autoionizing.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080604
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    Spin-orbit interaction in polyatomic molecules: Ab initio computations with Gaussian orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 941-950 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Standard sets of Gaussian atomic orbitals (STO-3G, STO-4.31G) are used to evaluate spin-orbit coupling constants in linear molecules (CO2+, NNN) and spin-orbit effects on singlet-triplet transition intensities in formaldehyde. All spin-other orbit effects have been included. In all cases spin-other orbit interactions form a large fraction of the matrix elements. Simple formulae to evaluate spin-orbit one- and two-electron integrals over atomic orbitals are presented. Standard molecular integral programs can be used for the computation of spin-orbit integrals.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080609
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    Error analysis of variationally optimized upper- and lower-bound wave functions for H2+Work supported in part by the National Research Council of Canada. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 971-980 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wave functions which are a linear combination of H2+-type elliptical orbitals are optimized to provide either an upper bound or a lower bound to the H2+ ground state. For the latter, Temple's formula is used. Three criteria are considered to determine the relative accuracy of these wave functions: (i) energy (calculated versus exact eigenvalue); (ii) average error; and (iii) local energy. Although the lower-bound optimized wave functions obtained are the most accurate available for H2+ from approximate wave functions, they are still inferior to the corresponding upper-bound wave functions by criteria (i) and (ii). In particular, using criterion (ii), it is shown numerically that the upper-bound functions are “correct to second order,” while the lower-bound functions are almost, but not quite, “correct to second order.” Despite this, the local energy analysis, criterion (iii), reveals that the lower-bound wave functions can be more accurate than the upper-bound functions in some regions of space, and hence give more accurate values for physical properties sensitive to these regions. Examples considered are the dipole-dipole and Fermi contact interactions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080611
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  • 80
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    Variation of the polarizability of the hydrogen molecule ion and the hydrogen molecule with internuclear separation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 91-95 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The variation of the polarizability of H2+ and H2 with internuclear separation R = 1.6 - R = 2.4 a.u. for H2+ and R = 1.0 - R = 2.0 a.u. for H2 is determined using a variational method suggested by Das and Bersohn. From these data, values of 〈α〉0,J for which nuclear motion due to zero point vibration and centrifugal stretching is taken into account, are calculated at 300°K. The relative percent increases of the motion averaged values compared to the equilibrium values are as follows: 10.50% for H2+ and 6.52% for H2.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080110
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    Floating one-center perturbation treatments for H2+-like molecules based on screened hydrogen atom or molecular puff unperturbed problems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 119-136 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various floating one-center perturbation schemes are developed for H2+-like molecules. Previous work for the ‘1s’ hydrogen atom approach is extended through third order in the energy. In the molecular puff approach an exact ‘closed form’ solution is obtained for the zeroth-order problem, which corresponds to a double layer molecular puff. Semianalytical results for the first-order correction to the floating molecular puff wave function and for the energy through third order are developed which offer a convenient alternative to previous approaches. Explicit calculations for ground state H2+ show that for R 〉 3aO the ‘1s’ and the more complicated ‘puff’ treatments are equivalent and that neither the ‘1s’nor the molecular puff function is an adequate zeroth-order wave function for the important intermediate values of R. The usefulness of some of these methods in a variety of problems, where one-center zeroth-order wave functions do appear to be adequate, is discussed briefly.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080113
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  • 82
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    Accurate analytical self-consistent field wave functions for Tm2+ and Tm3+ (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 73-78 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The analytical expansion self-consistent field method was employed to perform ab initio calculations for the ground states of the rare-earth ions, Tm2+, 4f13, 2F, and Tm3+, 4f12, 3H, (Z = 69). In each case the total number of basis functions used in the analytical expansions was 29, distributed as follows: 10, 8, 5, and 6, for the symmetries s, p, d, and f, respectively. All of the orbital exponents of the basis functions were optimized repeatedly, to the extent of the single-precision computer representation. Values of 〈rn〉 for the 4f orbital of both ions are also presented, for the convenience of experimentalists.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080107
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    Coupled Hartree Fock calculation of static dipole polarizabilities and shielding factors of open shell systems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 97-105 
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    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Static dipole polarizabilities and shielding factors for the 2p open shell atomic systems are presented using coupled Hartree Fock theory in the framework of the Roothaan formalism. Calculations have been performed for the ground as well as for some valence excited states. A variational approach has been adopted for the determination of the first-order perturbed functions. The results are compared with those obtained from the correlated calculations and other techniques. The shielding factor values are in excellent agreement with the theoretical N/Z ratio.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080111
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  • 84
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    Electronic Resource
    Extended Hartree-Fock self-consistent field with some results for berylliumlike atomic systems (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 839-855 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The general methods of deriving the extended Hartree-Fock equations are described. The rules for going over from the energy expression in the ordinary method of calculation to that in an extended one are reformulated and illustrated. The extended Hartree - Fock equations for berylliumlike atomic systems based on the use of nonorthogonal radial orbitals are given and solved. The numerical values of overlap integrals and total energies are given and discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080603
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  • 85
    Electronic Resource
    Electronic Resource
    Dynamic polarizability of helium: A random phase approximation calculation (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 901-913 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The random phase approximation (RPA) or time-dependent Hartree-Fock approximation (TDHF) is reconsidered for the calculation of the dynamic polarizability for atoms. An integral equation which admits a simple numerical treatment is established. The asymptotic approximation for the electron propagator is tested for its applicability by means of comparisons with earlier results.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080606
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  • 86
    Electronic Resource
    Electronic Resource
    Book Reviews (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 995-995 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080613
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  • 87
    Electronic Resource
    Electronic Resource
    Molecular integrals over generalized gaussian basis sets (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 179-191 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is given for obtaining the common molecular integrals over generalized gaussian functions: \documentclass{article}\pagestyle{empty}\begin{document}$$ \chi_i = x^{\lambda_i}_i \exp \big\{ - \big(\alpha_i x^2_i + \alpha^{\prime}_i x^{\prime 2}_i + \alpha^{\prime\prime}_i x^{\prime\prime 2}_i\big)\big\} $$\end{document}The present algorithms are expected to be more efficient than those given in earlier work by the same author.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080205
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  • 88
    Electronic Resource
    Electronic Resource
    On the need of precision in the calculation of the LCAO density matrix of polymers (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 201-208 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper, we point out how the precision of the LCAO density matrix elements of polymers may affect the computed properties. We propose to use a more adapted approach in order to evaluate these quantities.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080207
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  • 89
    Electronic Resource
    Electronic Resource
    The Coulomb hole in the 23S state of the helium isoelectronic sequence (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 255-261 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pair distribution functions evaluated for the 23S state of the helium isoelectronic sequence from the Hart and Herzberg correlated wave functions and those corresponding to the Hartree-Fock approximation are used to determine the shape of the corresponding Coulomb holes. As a consequence of a discontinuity in the Hartree-Fock solution between He and Li+, the Coulomb hole has a different shape for He than for Li+ and the other isoelectronic ions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080212
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  • 90
    Electronic Resource
    Electronic Resource
    Oscillator and hydrogenic matrix elements by operator algebra (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 585-604 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Occupation number representation of the two-dimensional harmonic oscillator and some operator formulae are used in a simple algebraic derivation of complicated integrals. The calculation of full oscillator- and radial integrals of r̂w and exp (\documentclass{article}\pagestyle{empty}\begin{document}$ (iw\hat{\varphi})$\end{document}), where w is an arbitrary positive or negative integer, are performed by an integral transform, leading to a generalized Gauss matrix element. Thus it is possible, because of the back transformation, to derive from one generalized Gauss matrix element all matrix elements which are permitted by the selection rules. Some integrals of r̂w and exp (\documentclass{article}\pagestyle{empty}\begin{document}$ (iw\hat{\varphi})$\end{document}), Laguerre polynomials, and Bessel functions are completely new. For the already known integrals, the mathematical labour is considerably reduced. The relation between the two-dimensional oscillator and the hydrogen atom and their angular momentum properties are discussed. A survey on the various methods applied to the oscillator problem, from complex integration to noncompact Lie groups, and a comprehensive bibliography on this important spectroscopic field are given.
    Additional Material: 604 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080409
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  • 91
    Electronic Resource
    Electronic Resource
    Electron correlation study for two-electron atoms by a simple correlated wave function (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 755-764 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The difference in the electron correlation between H- and other two-electron atoms is clarified by the introduction of the r12 term in the wave function. By using the expansion of r12, a certain modification of the usual electron correlation factor 1 + Cr12 is introduced and its effectiveness is examined. Calculations are carried out for the ground state and the three lowest excited states (23S, 23P and 21P). The peculiar electron correlation in the ground state of H- is shown by looking at the Coulomb hole for closed- and open-shelf models in comparison with those for other two-electron atoms.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080510
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  • 92
    Electronic Resource
    Electronic Resource
    Virtual orbital transformation prior to configuration interaction with localized orbitals (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 777-782 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A virtual orbital transformation is proposed involving pairing of localized occupied orbitals with virtual orbitals. The virtual orbitals are transformed so that each virtual orbital is as “close” as possible to its occupied counterpart, where closeness is the inverse of the particular definition of localization. The appropriate transformation is derived for the special case of Foster-Boys localization, and an illustrative CNDO/2 calculation on HNO is presented. INDO CI results on the series N2, CO, BF indicate that use of this transformation may reduce the number of energetically significant configurations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080512
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  • 93
    Electronic Resource
    Electronic Resource
    Molecular orbitals of nitrogen at small internuclear distances (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 817-821 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080516
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  • 94
    Electronic Resource
    Electronic Resource
    Masthead (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080601
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  • 95
    Electronic Resource
    Electronic Resource
    Perturbative ab initio calculations of intermolecular energies. I. Method (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 1-15 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from a knowledge of approximate wave functions of the isolated molecules (or atoms) A and B, a method is proposed to build up a zeroth-order ground state and excited configurations for the complex AB in which the molecular orbitals keep their local significance. The standard Rayleigh-Schrödinger perturbation in this basis provides a decomposition of the zeroth-order interaction energy as a sum of the electrostatic and repulsion energy. In the second order, it is possible to identify the classical dispersion and polarization forces (modified by a term of order S2) and two additional contributions which are linked to the exchange possibility. The intramolecular correlation component is taken into account and compared with the correlation on the isolated molecules. It is moreover suggested that since we work in a rather limited basis set, the perturbed energy of AB must be compared with the unperturbed energies of A and B calculated in a basis including the vacant orbitals on their respective partner. Finally a possibility for going beyond the second order is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080102
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  • 96
    Electronic Resource
    Electronic Resource
    Matrix formulation of the generalized Hartree-Fock methods (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 45-60 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Spin-projected one-particle density and spin density matrices are presented as polynomials of suitable unprojected quantities with generalized Sasaki-Ohno coefficients. Thus an explicit form of Harriman's theorems is given. For the two-particle spatial density matrix an expansion in direct products of powers of unprojected residual electron and spin density matrices is given. For these basic matrices of the scheme the variational spin-extended equations are formulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080105
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  • 97
    Electronic Resource
    Electronic Resource
    Symmetry adaptation and the relation between the spin-free and space-spin formulations of electronic structure (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 223-233 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An information-theoretic degree of symmetry adaptation of a ket with respect to a given group is introduced. Then the general equivalence between spin-free electronic kets and antisymmetrized space-spin kets is obtained so long as our attention is restricted to spin-independent observables. It is noted that there are spin-free kets for which there exists no single antisymmetrized space-spin ket giving all the same expectation values; the converse is also noted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080209
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  • 98
    Electronic Resource
    Electronic Resource
    Transformation properties of many-electron wave functions with special attention to the relation between pair-correlated DODS and configuration interaction (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 715-732 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is presented that leads to a simple derivation of the explicit relation between pair-correlated DODS schemes (e.g., the alternant molecular orbital method and the extended valence bond method) and configuration interaction.This result is based on a reduction formula for the representations of the general linear group, GL(m), carried by the N-electron function space. Generally, this paper deals with the effect of “partitioned” orbital transformations on states with “local” permutation symmetry.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080507
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  • 99
    Electronic Resource
    Electronic Resource
    Ab initio calculations on porphin (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 915-924 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio SCF calculations are reported for the porphin molecule. The positions of the central protons have been optimized, and the equilibrium geometry is found to be a linear NH ⃛ HN arrangement. The NH vibrational frequencies have been computed and are compared to experimentally measured quantities. Several low ionized states have also been studied in separate spin-restricted SCF calculations. The lowest state is found to have B1u symmetry with an ionization potential of 8.0 eV.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080607
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  • 100
    Electronic Resource
    Electronic Resource
    Basis dependence of wave functions of the ground state and low-lying excited states of planar formaldehydeThis is a part of a thesis for the Ph.D degree conferred by the Hokkaido University. (1974)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 8 (1974), S. 981-993 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By the use of three bases containing 3p STO's possessing different diffuseness, the electronic structure of several excited states (valence- and Rydberg-type) of planar formaldehyde is investigated by limited CI calculations. The spatial extension of the valence-type state is independent of the bases, whereas a diffuse orbital is important in describing the Rydberg-type state. The natural orbital analysis shows that the Rydberg-type states can be described as an outer electron plus an electronic cloud representing the ionized state to which the Rydberg states converge.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080612
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