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COMPARISON OF LOCAL-DENSITY AND HARTREE-FOCK CALCULATIONS OF MOLECULAR POLARIZABILITIES AND HYPERPOLARIZABILITIES

TitleCOMPARISON OF LOCAL-DENSITY AND HARTREE-FOCK CALCULATIONS OF MOLECULAR POLARIZABILITIES AND HYPERPOLARIZABILITIES
Publication TypeJournal Article
Year of Publication1993
AuthorsGuan, JG, Duffy, P, Carter, JT, Chong, DP, Casida, KC, Casida, ME, Wrinn, M
JournalJournal of Chemical Physics
Volume98
Pagination4753-4765
Date PublishedMar
Type of ArticleArticle
ISBN Number0021-9606
KeywordsATOMS, BASIS-SETS, CLOSED-SHELL, ELECTRIC POLARIZABILITIES, FINITE-FIELD CALCULATIONS, HYDROGEN-FLUORIDE, INDUCED POLARIZATION FUNCTIONS, PERTURBATION CORRELATION CORRECTIONS, RAMAN-SPECTRUM, STATIC DIPOLE POLARIZABILITIES, WATER MOLECULE
Abstract

This paper presents a comparison between density functional theory local density approximation (LDA) and Hartree-Fock approximation (HFA) calculations of dipole moments, polarizabilities, and first hyperpolarizabilities, using ’’comparable’’ basis sets, in order to assess the relative quality of the LDA and the HFA for calculating these properties. Specifically, calculations were done using basis sets of roughly double or triple zeta plus polarization quality, with and without added field-induced polarization (FIP) functions, for the seven small molecules H-2, N2, CO, CH4, NH3, H2O, and HF, using the HFA option in the program HONDO8 and the LDA options in the programs DMol and deMon. For the calculations without FIP functions, the results from HONDO8 HFA and deMon LDA, both of which use Gaussian basis sets, are very similar, while DMol, which uses a LDA numerical atomic orbital basis set, gives substantially better results. Adding FIP functions does much to alleviate these observed basis set artifacts and improves agreement with experiment. With FIP functions, the results from the two sets of LDA calculations (deMon and DMol) are very similar to each other, but differ markedly from the HFA results, and the LDA results are in significantly better agreement with experiment. This is particularly true for the hyperpolarizabilities. This appears to be the first detailed study of DFT calculations of molecular first hyperpolarizabilities. We note that closer attention to numerical details of the finite field calculation of beta over arrow pointing both left and right is necessary than would usually be the case with traditional ab initio methods. A proof that the Hellmann-Feynman theorem holds for Kohn-Sham calculations is included in the Appendix.

URL<Go to ISI>://A1993KU22200045