Performance of Becke's exchange functional fitted for Gaussian basis sets

Abstract

Equilibrium geometries, dipole moments, harmonic vibrational frequencies and atomization energies for a set of 32 small neutral molecules were calculated with the 6-31G ∗ standard basis set and approximate density functional theory methods. Comparison with experimental results confirmed that selecting properly the β parameter in the Becke's gradient corrected exchange functional results in a better overall fit for all the molecular properties studied. In particular the atomization energies are noticeably improved, and for other properties slightly better results are always obtained.