Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles: DFG German National Licenses  (25)
  • Computational Chemistry and Molecular Modeling  (24)
  • First-row atoms  (1)
  • 11
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 605-613 
    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
    Description / Table of Contents: A time-saving way of programming an SCF method for molecules (SCF—MO—LCGO method) is proposed, which is based on an economic way of handling the two-electron-multicenter integrals.
    Abstract: On présente un programme efficace pour des calculs SCF moléculaires, dont l'efficacité dépend d'un traitement rationnel des intégrales à deux centres.
    Notes: Es wird eine rechenzeitsparende Programmierung eines SCF-Verfahrens für Moleküle (SCF—MO—LCGO-Verfahren) angegeben, die auf einer rationellen Behandlung der Zweielektronen-Mehrzentrenintegrale beruht.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 641-644 
    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
    Description / Table of Contents: The system (Li2H)- has been investigated ab initio for several nuclear positions, taking all eight electrons into account, using the Allgemeines Programmsystem/SCF—MO—LC(LCGO) Verfahren. A stable molecule was found for the linear symmetric configuration with a bond distance of RLiH = 3.41 a.u., and a total energy of -15.3874 a.u., which is about 0.0114 a.u. (0.311 eV, 7.61 kcal/mole) lower than the sum of the comparable SCF energies of the systems LiH and Li-. The force constant of the symmetric vibration was estimated to be k = 1.64722 × 106 dyn/cm and the frequency to be ω = 1998.9 cm-1. The results are discussed.
    Abstract: En tenant compte de tous les huit électrons on a fait des calculs pour le (Li2H)- pour une série de positions nucléaires. On trouve pour une configuration linéaire une molécule stable, de distance de liaison RLiH = 3,41 u.a. et d'énergie totale -15,3874 u.a. Cette énergi-ci est plus basse que la somme des énergies des systèmes LiH et Li- de 0,0114 u.a. (0,311 eV, 7,61 kcal/mole). La constante de force de vibrations symmétriques est 1,64722 × 106 dyn/cm, ce qui correspond à une fréquence ω = 1998,9 cm-1.
    Notes: Das System (Li2H)- wurde für eine Reihe von Kernlagen unter Berücksichtigung aller 8 Elektronen mit dem Allgemeinen Programmsystem/SCF—MO—LC(LCGO) Verfahren berechnet. Es ergab sich für die lineare symmetrische Anordnung ein stabiles Molekül mit dem Bindungsabstand RLiH = 3,41 a.E. und einer Gesamtenergie von -15,3874 a.E., die um 0,0114 a.E. (0,311 eV, 7,61 kcal/mol) tiefer liegt als die Summe der entsprechenden SCF-Energien der Systeme LiH und Li-. Die Kraftkonstante der symmetrischen Schwingung ergibt sich zu k = 1,64722 × 106 dyn/cm, aus der die Frequenz zu ω = 1998,9 cm-1 berechnet wurde. Die Ergebnisse werden diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 631-635 
    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
    Description / Table of Contents: The system (LiH2)- has been investigated for several nuclear positions, taking all six electrons into account, using the Allgemeines Programmsystem/SCF—MO—LC (LCGO) Methode. A metastable molecule was found having a linear configuration (RLiH = 3.5 ± 0.2 a.u.) and a total energy 0.12 a.u. lower than that of the separated atoms. On the other hand, (LiH2)- can dissociate into Li- + H2; the total energy of which is 0.01 a.u. smaller. The potential barrier for this process is found to be 0.15 a.u. The energy hypersurface is given graphically and the formation (as well as the decomposition) of (LiH2)- is discussed.
    Abstract: On décrit un calcul de système (LiH2)- pour une série de positions nucléaires, basé sur Allgemeines Programmsystem/SCF—MO—LC(LCGO) Methode. Tous les six électrons ont été considérés. On trouve pour la configuration linéaire (RLiH = 3,5 ± 0,2 u.a.) une molécule métastable, dont l'énergie totale est plus basse que celle des atomes séparés de 0,12 u.a. D'autre part le (LiH2)- peut dissocier en Li- + H2, d'énergie totale 0,01 u.a. plus basse. La barrière de potentiel de ce procès-ci est 0,15 u.a. On discute en détail, par une méthode graphique, la formation et la décomposition du (LiH2)-.
    Notes: Das System (LiH2)- wurde für eine Reihe von Kernlagen unter Berücksichtigung aller 6 Elektronen mit dem Allgemeinen Programmsystem SCF—MO—LC(LCGO) Mathode berechnet. Es ergab sich, dass für die lineare Anordnung (RLiH = 3,5 ± 0,2 a.E.) ein metastabiles Molekül vorliegt, dessen Gesamtenergie um 0,12 a.E. tiefer liegt als das System der getrennten Atome. Dagegen kann (LiH2)- über einen Potentialberg in Li- + H2 zerfallen, welches um 0,01 a.E. tiefer liegt. Die Höhe des Potentialberges beträgt 0,15 a.E. Die Energiehyperfläche wird graphisch dargestellt und im Einzelnen die Bildung (und der Zerfall) von (LiH2)- diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 637-640 
    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
    Description / Table of Contents: The (Li2H)+ has been investigated ab initio in the linear configuration, with the H atom in the middle of the system, for five different distances RLiH, taking all six electrons into account, using the Allgemeines Programmsystem/SCF—MO—LC(LCGO) Verfahren. A bond distance RLiH of 3.14 a.u., a total energy of -15.289 a.u., and an ionization energy of 15.1 eV were found. Comparing the results of SCF investigations, the formation energy of (Li2H)+ from LiH and Li+ was computed to be 59.7 kcal/mole (2.58 eV). Using the energy curve near the minimum, a force constant for the symmetric vibration of k = 0.13777 × 106 dyn/cm and a frequency ω = 577.9 cm-1 were found.
    Abstract: En tenant compte de tous les six électrons on a fait des calculs pour le (Li2H)+ dans le cas linéaire pour cinq distances différentes RLiH et avec l'atome H au milieu. On trouve au minimum une énergie totale de -15,289 u.a. et une distance de liaison RLiH de 3,14 u.a. L'énergie d'ionization correspondante est 15,1 eV. L'énergie de formation du LiH et du Li+ a été obtenue en comparant les calculs SCF des trois systèmes, ce qui donne 59,7 kcal/mole (2,58 eV). La courbe de potentiel près du minimum donne une constante de force de vibrations symmétriques de 0,13777 × 106 dyn/cm, ce qui correspond à une fréquence de 577,9 cm-1.
    Notes: Das (Li2H)+ wurde unter Berücksichtigung aller 6 Elektronen mit dem Allgemeinen Programmsystem/SCF—MO—LC(LCGO) Verfahren im linearen Fall für 5 verschiedene Abstände RLiH berechnet, wobei das H-Atom in der Mitte lag. Es ergab sich im Minimum eine Gesamtenergie von -15,289 a.E. der Bindungsabstand RLiH berechnet sich zu 3,14 a.E. Die Ionisierungsenergie beträgt dabei 15,1 eV. Die Bildungsenergie aus LiH und Li+ ergibt sich beim Vergleich der SCF-Rechnungen an den beteiligten Systemen zu 59,7 kcal/mol (2,58 eV). Aus der Potentialkurve in der Nähe des Minimums berechnet sich die Kraftkonstante der symmetrischen Schwingung zu k = 0,13777 × 106 dyn/cm, aus der eine Frequenz ω = 577,9 cm-1 resultiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 645-647 
    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
    Description / Table of Contents: The (CH3)+ has been investigated ab initio, taking all 8 electrons into account, using the Allgemeines Programmsystem/SCF—MO—LC(LCGO) Verfahren. After varying the C—H distance and the position of the C atom, it was found that the (CH3)+ ion is planar with a bond distance of RCH = 2.05 a.u. The force constants (C—H stretching, angular vibration) were computed to be k1 = 18.9 mdyn/Å, and the associated frequencies to be ω1 = 3256 cm-1 and ω2 = 1526 cm-1. The ionization energy was found to be I = 25.75 eV. The electron affinity was estimated to be A = 5.4 eV.
    Abstract: En tenant compte de tous les huit électrons on a fait des calculs du système (CH3)+. On a varié la distance C—H ainsi que la position de l'atome C et on trouve que tous les atomes sont situés dans un plan avec la distance RCH = 2,05 u.a. Les deux constantes de force resultantes sont k1 = 18,9 mdyn/Å et k2 = 3,3 mdyn/Å avec les nombres d'ondes correspondants ω1 = 3256 cm-1 et ω2 = 1526 cm-1. Pour l'énergie d'ionisation on trouve 25,75 eV et pour l'affinité électronique 5,4 eV.
    Notes: Das (CH3)+ wurde unter Berücksichtigung aller 8 Elektronen ab initio mit dem Allgemeinen Programmsystem/SCF—MO—LC(LCGO) Verfahren berechnet. Es ergab sich nach Variation des C—H Abstandes und der Lage des C Atoms, dass (CH3)+ eben gebaut ist, mit einem Bindungsabstand RCH = 2,05 a.E. Die beiden Kraftkonstanten (Atmungsschwingung, Winkelschwingung) ergeben sich dabei zu k1 = 18,9 mdyn/Å und k2 = 3,3 mdyn/Å mit den zugehörigen Wellenzahlen ω1 = 3256 cm-1 und ω2 = 1526 cm-1. Die Ionisierungsenergie wurde zu I = 25,75 eV bestimmt. Die Elektronenaffinität wurde zu A = 5,4 eV abgeschätzt.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 649-652 
    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
    Description / Table of Contents: The (OH)- has been investigated ab initio for four different distances ROH taking all 10 electrons into account, using the Allgemeines Programmsystem/SCF—MO—LC(LCGO) Method. The equilibrium distance ROH was estimated to be 1.82 a.u., the minimum of the total energy to be -75.305 a.u. and the ionization energy of (OH)- (electron affinity of OH) to be 2.29 eV. The force constant was computed to be k = 7.47 mdyn/Å with a frequency of ω = 3655 cm-1.
    Abstract: En tenant compte de tous les dix électrons on a fait des calculs pour l'ion (OH)- pour quatre distances nucléaires différentes. On trouve un minimum d'énergie de -75,305 u.a. pour la distance R = 1,82 u.a. L'énergie d'ionisation du (OH)- est 2,29 eV, la constante de force 7,47 mdyn/Å et la fréquence correspondante ω = 3655 cm-1.
    Notes: Das (OH)- wurde unter Berücksichtigung aller 10 Elektronen mit dem Allgemeinen Programmsystem/SCF—MO—LC(LCGO) Verfahren für 4 verschiedene Kernabstände berechnet. Es ergab sich ein Energieminimum bei einem Abstand von R = 1,82 a.E. mit einer Gesamtenergie von ∊ = -75,305 a.E. Für die Ionisierungsenergie des (OH)- (Elektronenaffinität des OH) ergab sich ein Wert von 2,29 eV. Die Kraftkonstante wurde zu k = 7,47 mdyn/Å bestimmt, die zugehörige Frequenz beträgt ω = 3655 cm-.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 19 (1981), S. 113-130 
    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: Semilocal pseudopotentials have been determined for first-row (Li to Ne), second row (Na to Ar), and third-row atoms (K, Ca). Core-valence correlation is included by adjusting the pseudopotentials to experimental energies of ions with a single valence electron. Correlation within the valence shell is taken into account by using the spin-density functional formalism. The approximations involved in this approach are tested for atomic ionization energies as well as binding energies of monohydrides and alkali diatomics, agreement with experiment is usually satisfactory, but in certain applications density functionals should be already included in the fitting of the local part of the pseudopotential. In addition, 3s/3p and 3s/2p basis sets (for first and second row, respectively), designed for use in connection with our pseudopotentials, are given; it is shown that they yield reasonable results for both SCF and correlation energies.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 3 (1969), S. 881-887 
    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 ethylene molecule has been investigated by means of the General SCF-MO-LC(LCGO) Program System for 12 different nuclear positions, taking all electrons into account. The equilibrium distances and angles as well as all force constants of the totally symmetric vibrations with the corresponding frequencies have also been calculated.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 3 (1969), S. 123-130 
    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 first part of this paper gives an introduction of different kinds of atomic associations. Furthermore it will be shown that partial systems of united atoms are not only described by their nuclear-charge number, but additionally by their number of electrons. Both characteristics of a partial system of atomic associations may lead to an apparent multiple-valuedness in the transitions between atomic associations. It is shown that the multiple-valuedness of the atomic associations can be understood and eliminated within the Born-Oppenheimer-approximation, which leads to the concept “energyhypersurface”. An example is given by the system {He, H, H, H}+.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 9 (1975), S. 775-787 
    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 described for calculating cohesive energies of solids in the single-determinant approximation including the full Hartree-Fock exchange. The method involves (1) the construction of a rapidly convergent series in vectors of the direct and reciprocal lattice for the Fock matrix, (2) a decoupling procedure for the k-dependence of the Fock matrix, which works even in the case of strong interatomic overlap. An application to Li and Be is given. Agreement with experiment to 10% is achieved for the cohesive energies and to 5% for the equilibrium lattice constants.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...