Localized Orbitals in Polyatomic Systems

Abstract

Abstract Adams und Gilbert have derived a rigorous extension to the Hartree‐Fock equation which allows one to obtain localized orbitals in some polyatomic systems. This extension is valid for all closed shell systems and all systems which may be represented by a single Slater determinant and is approximately valid for any system which one may approximate by a single Slater determinant. In this paper these results are put in a more convenient form and are analysed in powers of the interatomic overlap, where only first order terms in overlap are retained. A perturbative form of the equation is also developed. Wave functions are obtained for the LiH crystal.