Premium
Distributed basis sets of s‐type Gaussian functions for simple diatomics: Anharmonic‐model distribution
Author(s) -
Glushkov V. N.,
Wilson S.
Publication year - 2007
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.21428
Subject(s) - anharmonicity , diatomic molecule , ground state , hartree , gaussian , hartree–fock method , basis set , basis (linear algebra) , chemistry , physics , atomic physics , quantum mechanics , molecule , mathematics , geometry
An anharmonic model for systematically distributing Gaussian basis sets is presented. Illustrative calculations demonstrate the new approach for the H 2 + , HeH 2+ and H 2 diatomic systems. The total ground state energies for the one‐electron systems and the ground state Hartree‐Fock energy for the H 2 molecule supported by distributed basis sets constructed by means of the anharmonic model are compared with the corresponding energies obtained by invoking the variation principle to determine optimal exponents and positions. The use of a series of anharmonic distributions of s ‐type Gaussian functions centred on regularly spaced points is also investigated. Calculated energy expectation values supported by our largest distributed basis sets differ from the corresponding exact values by 0.70 μHartree for the H 2 +ion and by 0.89 μHartree for the HeH 2+ ion. For the ground state Hartree‐Fock energy of the H 2 molecule, our distributed basis set yields a value which differs from the finite difference Hartree‐Fock value by 0.67 μHartree. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007