Abstract
A numerical Hartree-Fock procedure is described for computing wave functions for nsnsS1 configurations in which the radial functions for the two s electrons are not assumed to be orthogonal. When the two s electrons are equivalent, this approach corresponds to the unrestricted Hartree-Fock approximation. The procedure was applied to some 2- and 4-electron systems. Results are reported for 1s1sS1 of He, Li+, and Be2+ as well as 1s1s(S1)2snsS1, n=2, 3, 4 of Be. The total energies are compared with those of other approximations, and the transition integrals for the unrestricted approximation are shown to differ only slightly from those of the Hartree-Fock approximation.