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Calculations using a set of evenly spaced S ‐type gaussian functions
Author(s) -
Jensen James O.,
Leonard Joseph M.
Publication year - 1991
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560390206
Subject(s) - basis set , basis (linear algebra) , sto ng basis sets , gaussian , atomic orbital , set (abstract data type) , basis function , type (biology) , electron , atomic physics , mathematics , lithium (medication) , physics , chemistry , statistical physics , molecule , quantum mechanics , mathematical analysis , linear combination of atomic orbitals , geometry , computer science , ecology , biology , programming language , medicine , endocrinology
A basis set of evenly spaced S ‐type Gaussian functions with common exponents is examined. Formulas for common one‐ and two‐electron integrals are derived. Because of thesymmetry of this basis set, a very compact two‐electron integral list is produced. The number of two‐electron integrals that must be stored is approximately eight times the number of basis functions. Use of this basis set in an SCF calculation is examined. Numerical results show that this approach works well for molecules containing only small atoms such as hydrogen, helium, or lithium, but that the method has problems with the core orbitals of heavier atoms. Procedures for augementing this basis set in calculations involving heavier atoms are examined.