PERFORMANCE OF BECKE EXCHANGE FUNCTIONAL FITTED FOR GAUSSIAN-BASIS SETS

Equilibrium geometries, dipole moments, harmonic vibrational frequenci es and atomization energies for a set of 32 small neutral molecules we re calculated with the 6-31G standard basis set and approximate densi ty functional theory methods. Comparison with experimental results con firmed that selecting properly the beta parameter in the Becke's gradi ent corrected exchange functional results in a better overall fit for all the molecular properties studied. In particular the atomization en ergies are noticeably improved, and for other properties slightly bett er results are always obtained.