Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Etude de la structure du cortège électronique par la méthode des états de valence (1965)
    Springer
    Theoretical chemistry accounts 3 (1965), S. 384-397 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Starting with Dirac's theory, we build up a Hamiltonian for an atomic system with several electrons. The investigation of different ways of constructing the state space of the polyelectronic system leads to the definition of “electronic configuration” and “valence state”. Using these concepts a method for calculating the atomic wave functions is set forth, which allows a precise determination of spectral term energies.
    Abstract: Zusammenfassung Ausgehend von der Diracschen Theorie des Elektrons geben wir einen Hamilton-Operator für ein atomares System mit mehreren Elektronen an. Die Begriffe „Elektronenkonfiguration“ und „Valenzzustand“ werden bei der Untersuchung des Zustandsraumes des Mehr-elektronensystems definiert. Mit ihrer Hilfe wird ein Verfahren zur Berechnung der atomaren Wellenfunktionen entwickelt, das eine genaue Bestimmung der Termenergien erlaubt.
    Notes: Résumé Partant de la description de Dirac, on construit l'hamiltonien d'un système atomique polyélectronique. En étudiant différents modes de construction de l'espace des états du système polyélectronique, on définit les termes ≪configuration électronique≫ et ≪état de valence≫. Puis, à l'aide de ces concepts, on expose une méthode de calcul des fonctions d'onde atomiques permettant, en outre, une détermination précise des énergies des termes spectraux.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00530416
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Etude de la structure du cortège électronique par la méthode des états de valence (1965)
    Springer
    Theoretical chemistry accounts 3 (1965), S. 398-406 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract The method of valence states previously described, is applied to the ground configuration of the neutral carbon atom. The term energies obtained are (in Rydbergs) 3 P: — 75.47900, 1 D: — 75.36826, and 1 S: — 75.30856, with errors below 4%.
    Abstract: Zusammenfassung Die früher beschriebene Methode der Valenzzustände wird auf die Grundkonfiguration des neutralen C-Atoms angewandt. Man erhält folgende Termenergien (in Rydberg): 3 P: — 75,47900, 1 D: — 75,36826 und 1 S: — 75,30856, mit Fehlern unter 4%.
    Notes: Résumé La méthode des états de valence décrite précédemment est appliquée à l'état fondamental de l'atome neutre de Carbone. On obtient les valeurs suivantes des énergies associées aux termes spectraux 3 P,1 D et 1 S: — 75,47900, — 75,36826 et — 75,30856 en unités Rydberg. L'erreur relative reste inférieure à 4 pour mille.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00530417
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Evaluation des facteurs de diffusion bicentriques par la méthode de la fonction zeta (1968)
    Springer
    Theoretical chemistry accounts 9 (1968), S. 230-241 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Résumé Le développement sur un centre unique de distributions de charge bicentriques est utilisé dans l'évaluation des facteurs de diffusion. On donne les expressions analytiques des diverses intégrales, valeurs «ponctuelles» et valeurs moyennes sur une base de fonctions de Slater de nombre quantique principal n ≤ 2. Les différentes techniques de calcul employées sont développées en appendice.
    Abstract: Zusammenfassung Die Entwicklung einer Zweizentrenladungsverteilung um ein Zentrum wird benützt, um Diffusionsfaktoren zu berechnen. Die analytischen Ausdrücke für die verschiedenen Integrale werden angegeben, und zwar einfache wie über eine Basis von Slaterfunktionen mit Hauptquantenzahl ≤ 2 gemittelte Werte. Die benutzten Rechenverfahren sind im Appendix zusammengestellt.
    Notes: Abstract The expansion of a two-center charge distribution about one center is utilized to calculate diffusion factors. The analytical expressions for the various integrals employed are given, both for the single case and averaged over a basis of Slater functions having a principal quantum number ≤ 2. The different methods of calculation used are summarized in an appendix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00526602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Calcul des facteurs de diffusion polycentriques sur une base de fonctions Gaussiennes (1968)
    Springer
    Theoretical chemistry accounts 9 (1968), S. 375-381 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Résumé L'évaluation des facteurs de diffusion polycentriques se trouve considérablement simplifiée lorsqu'on substitue à la base usuelle des fonctions de Slater, un développement en termes de fonctions Gaussiennes. On donne les expressions analytiques de ces facteurs de diffusion: valeurs ≪ponctuelles≫ et valeurs moyennes. Un exemple numérique permet de confronter les résultats obtenus avec ceux issus d'une autre méthode.
    Abstract: Zusammenfassung Die Berechnung von Mehrfach-Streufaktoren vereinfacht sich beträchtlich, wenn man eine Entwicklung nach Gaußfunktionen an Stelle der üblichen Slaterfunktionen vornimmt. Analytische Ausdrücke solcher Streufaktoren werden angegeben, und zwar sowohl für punktuelle als auch gemittelte Werte. Ein numerisches Beispiel zum Vergleich der Ergebnisse mit denen eines anderen Verfahrens wird angeführt.
    Notes: Abstract The evaluation of multi-center scattering factors is considerably simplified when an expansion in terms of Gaussian functions is substituted to the usual basis of Slater functions. Analytic expressions of such scattering factors are given: “point” values and average values. A numerical example allows comparison of the results with those obtained by another method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00526397
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Quelques intégrales utiles en chimie théorique (1965)
    Springer
    Theoretical chemistry accounts 3 (1965), S. 111-116 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei der Berechnung der SCF-LCAO-MO's treten unter anderem Zweizentren-Durchdringungsintegrale auf. Wir berechneten diese Integrale (über Hilfsfunktionen) mit dem Potentialansatz von Goeppert-Mayer und Sklar für Atome mit radialsymmetrischer Elektronendichte.
    Abstract: Abstract The determination of SCF-LCAO-MO's involves, beside others, two-centre penetration integrals. Using auxiliary functions, we calculated them, with a Goeppert-Mayer and Sklar potential, for the atoms with saturated or pseudo-saturated shells.
    Notes: Résumé Le calcul des fonctions d'onde moléculaires en méthode L. C. A. O. auto-cohérente fait appel, entre autres, aux intégrales de pénétration bicentriques. Ces intégrales ont été calculées à l'aide d'un potentiel de Goeppert-Mayer et Sklar, pour les éléments à couches internes saturées ou pseudo-saturées. Les intégrales sont exprimées à partir de fonctions auxiliaires.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00526536
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Extended Hückel theory: A new population analysis and its application to forecast chemical bond lengths (1979)
    Springer
    Theoretical chemistry accounts 52 (1979), S. 1-17 
    Details
    ISSN: 1432-2234
    Keywords: EHT population analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Although widely used, the population analysis proposed by Mulliken has been contested by several authors. A new analysis, very easily computed on the orthogonal basis, is here proposed and applied to the EHT wave function. Under its usual presentation, the EHT method is unable to directly evaluate bond lengths through an energy minimum condition. However, it is possible to settle an empirical quadratic relation between the bond lengthR rs and a quantity calledp rs, similar to a bond population. Such relations are given for bonds of the CC, CN, CO, CS, CF, CCl, CBr, CH, NO and OH types. The examination of the variation of the bond population under a variation of the bond length has enabled us to prove that this semi-empirical relation was usable in an iterative process: starting from bond lengths taken from any systematic table, it is possible, for a given molecule, to evaluate the bond length consistent with experimental values within an accuracy of 0.03 Å. Some examples, concerning cyclic or acyclic molecules and various kinds of bonds, are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581696
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    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 
    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 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560080602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Electronic correlation studies. III. Self-correlated field method. Application to 2S ground state and 2P excited state of three-electron atomic systemsAbstracted from part of a thesis submitted by R. Lissillour to the University of Rennes, 1973. (1975)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 9 (1975), S. 627-634 
    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 self-correlated field method is based on the insertion in the group product wave function of pair functions built upon a set of correlated “local” functions and of “nonlocal” functions. This work is an application to three-electron systems. The effects of the outer electron on the inner pair are studied. The total electronic energy and some intermediary results such as pair energies, Coulomb and exchange “correlated” integrals, are given. The results are always better than those given by conventional SCF computations and reach the same level of accuracy as those given by more laborious methods used in correlation studies.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560090405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...