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Ab initio CPHF calculations of the static polarizability and second hyperpolarizability of small molecules: Comparisons between standard and moderately large basis sets augmented with diffuse functions
Author(s) -
Dory M.,
Beudels L.,
Fripiat J. G.,
Delhalle J.,
André J. M.,
Dupuis M.
Publication year - 1992
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.560420530
Subject(s) - hyperpolarizability , polarizability , chemistry , basis set , basis (linear algebra) , computational chemistry , ab initio , gaussian , molecular physics , cyclopropane , molecule , atomic physics , density functional theory , physics , mathematics , ring (chemistry) , geometry , organic chemistry
Static polarizability and second hyperpolarizability have been calculated for a number of small moleculesCO 2 , OCS, CS 2 , C 2 H 2 , C 2 H 6 , C 3 H 8 , cyclo‐C 3 H 6 , C 3 H 4 , C 3 H 6 , SiH 4 , Si 2 H 6 in the framework of the coupled‐perturbed Hartree‐Fock ( CPHF ) theory. The linear and nonlinear coefficients have been calculated with standard Gaussian basis sets and 3‐21 G bases moderately enlarged with diffuse functions. It is shown that the parallel component of the polarizability saturates rapidly, which suggests that a 3‐21 G basis containing s and p diffuse functions is sufficient to reproduce α zz . For the α xx and α yy components, a 3‐21 G basis with s , p , and d diffuse functions is required. In general, the concordance between α computed with this basis set and the experimental static polarizability is at least of the order of 80%. On the contrary, the computation of the second hyperpolarizability with the same basis set for CO 2 , CS 2 , and C 2 H 2 gives values that are 30% too low, compared to the experimental value. Better results are observed for ethane, propane, and cyclopropane for which the error is lower than 50%. The better agreement observed for the saturated compounds can probably be explained by their saturated character.