The use of slater orbitals in variational calculations involving one-electron Green's functions

The application of a minimum principle by Hall, Hyslop, and Rees is proposed for electronic systems. It is shown that the evaluation of the required two center molecular integrals involving one electron Green's functions may be facilitated by introduction of a particular class of trial functions. These functions incorporate the potential energy of the system as a weighting factor and Slater-type orbitals are then used as a basis set. The evaluation of the resulting integrals is discussed and illustrative calculations for the H2(+) ion are presented.