Supplementary d and f functions in molecular wave functions at large and small internuclear separations

✍ Scribed by Eric Magnusson

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 625 KB
• Volume: 14
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540140111

✦ Synopsis

The CO, C02, CS, CIF, and SO2 molecules were used to test the dependence of supplementary d and f function exponents to changes in bond lengths and bond angles in MO calculations utilizing Gaussian basis sets in Hartree-Fock and Moller-Plesset calculations. Using Dunning-Hay double zeta basis sets, optimizations were performed at internuclear separations from 100-200 pm and beyond. The energy cost of not reoptimizing d function exponents when bonds are stretched or compressed is much smaller for correlated calculations than for those at the Hartree-Fock level and is greatest at the lower end of the range of internuclear distances.

The problem is much less serious at all levels when multiple sets of d functions are used.