The dirac equation in the algebraic approximation:: VIII.: Comparison of finite basis set and finite element molecular Dirac-Hartree-Fock calculations for the H2, LiH, and BH ground states

Using basis sets of distributed s-type Gaussian functions with positions and exponents optimized so as to support Hartree-Fock total energies with an accuracy approaching the sub-muHartree level, Dirac-Hartree-Fock-Coulomb calculations are reported for the ground states of the H-2, LiH, and BH molecules at their respective equilibrium geometries. The calculated energies are compared with those obtained by Kullie et al. using the finite element technique for the Dirac-Hartree-Fock-Coulomb problem: Finite basis set calculations using the Dirac-Hartree-Fock-Breit approximation are also reported and compared with a first-order treatment of the frequency-independent Breit interaction. (C) 2002 Wiley Periodicals, Inc.