COULOMB PARAMETERS IN SIMPLE HUCKEL AND OMEGA TECHNIQUE MOLECULAR ORBITAL METHODS

Abstract

The well-known similarities of the simple Huckel and omega technique molecular orbital procedures for pi electrons to Pople's self-consistent field method are extended by considering systematic approximations to the latter. From the relationships found, Huckel-method Coulomb integrals and omega values for a variety of atoms (Be, B, C, N, O, F, Mg, Al, Si, P, S, Cl, Ge, As, Se, Sn, Sb, Te) are derived. The Huckel and omega Coulomb integrals are shown to be directly related to a recent definition of orbital electronegativity. The ability of the omega techniques to improve upon the Huckel-method charge distributions is discussed by use of an arbitrary but typical example.