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Theoretica chimica acta

, Volume 11, Issue 5, pp 441–451 | Cite as

A comparison of different contractions for molecular calculations with gaussian-type functions

  • C. Salez
  • A. Veillard
Commentationes

Abstract

The effect of various possible contractions of a gaussian basis set is investigated for atomic and molecular calculations. The gaussian basis set used consists of 11s-type functions and 7p-type functions. Atomic calculations for the atoms Li to F are reported with fourteen different contractions of the s orbitals. The effect of the same contractions has also been investigated for molecular calculations of LiH, BH, CH2, NH 2 , H2O, and FH, together with the effect of the contraction for the p orbitals and for the s orbitals of the hydrogen atom. It is shown that the contraction in itself does not affect seriously the quality of a molecular calculation, but that a wrong choice of the contraction can produce a poor result.

Keywords

Hydrogen Physical Chemistry Inorganic Chemistry Organic Chemistry Hydrogen Atom 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Zusammenfassung

Der Einfluß der verschiedensten Kontraktionen einer Basis von Gauß-Funktionen bei Berechnung atomarer oder molékularer Systeme wird untersucht. Diese Basis besteht zunächst aus 11 s-Funktionen und 7 p-Funktionen. 14 verschiedene Kontraktionen werden für die Atome Li bis F sowie für die Moleküle LiH, BH, CH2, NH 2 , H2O und FH getestet. Wie zu erwarten wird die Genauigkeit nicht wesentlich beeinflußt, solange man nur die „richtigen“ Kontraktionen wählt.

Résumé

On étudie l'effet des différentes contractions possibles d'une base de fonctions gaussiennes dans le cas d'atomes et de molécules. La base de fonctions gaussiennes comprend 11 fonctions du type s et 7 fonctions du type p. On donne les résultats de quatorze différentes contractions des orbitales s pour les atomes du Li à F ainsi que pour les molécules LiH, BH, CH2, NH - 2 , H2O et FH. L'effet de la contraction des orbitales p ainsi que des orbitales s des atomes d'hydrogène est également discuté pour les molécules CH2 et H2O. On montre que la contraction par elle-même n'affecte pas sensiblement les résultats obtenus a condition d'effectuer un choix judicieux parmi les contractions possibles.

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Copyright information

© Springer-Verlag 1968

Authors and Affiliations

  • C. Salez
    • 1
  • A. Veillard
    • 1
  1. 1.IBM Research LaboratorySan José

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