Correlated prolate–spheroidal wave function for two-electron diatomic systems

Abstract
For two-electron diatomic systems, the determination of a prolate–spheroidal wave function containing explicitly the interelectronic distance as a coordinate is investigated from the exact resolution of an approximate Schrödinger equation separated in such a way that the true potential is rigorously taken into account, the perturbing term being a kinetic one. Calculations are carried out for the total energy of H2, He2+2, and HeH+ in their ground state. Results are seen to be in good agreement with the best ones. Extension to effective two-electron diatomic problems such as alkali dimers is considered.