An application of the 1/Z expansion method to reorganization corrections of the Koopmans ionization energy of atomic valence state

Using the 1/Z expansion method coupled with the random spin vector model, the reorganization corrections of the Koopmans ionization energies of the atomic valence state whose spatial quantization is referred to the cartesian coordinate system were formulated up to the second order. The theoretical formulations were applied to the valence electron ionizations of s²x², s²xy and sxyz isoelectronic series. The reorganization corrections calculated with the resolvent expansion were in fairly good agreement with the corresponding terms calculated with the direct ΔSCF method using the analytical approximations to the Hartree—Fock atomic orbitals.