Unrestricted Hartree-Fock calculations for a cluster model of CoO

Abstract
Self-consistent unrestricted Hartree-Fock calculations are performance for a CoO6010- cluster imbedded in a Madelung potential field simulating the rest of the solid. The O 2p-like and Co 3d-like stakes mix but are non-interacting, implying d electron localisation. The widths of the correlated p-like and d-like states are 3.94 eV and 5.38 eV respectively and these values agree well with experimental photoemission results.