Distributed Gaussian basis sets: Variationally optimized s-type sets for H2, LiH, and BH

Abstract

Distributed basis sets of s-type Gaussian functions are determined by invoking the variation principle for the Hartree-Fock ground states of the H2, LiH, and BH molecules at their respective experimental equilibrium geometries. The calculated energy expectation values supported by these finite basis sets are compared with finite difference Hartree-Fock energies reported by Kobus et al. A distributed basis set of 54 s-type Gaussian functions distributed along the internuclear axis is shown to support an accuracy of 0.05 μHartree for the Hartree-Fock ground-state energy of the H2 molecule while a similar set containing 50 functions leads to an accuracy of 0.8 μHartree for the ground-state ener..