Relationships between the semiempirical and the Hartree-Fock methods in band structure calculations

Abstract

We established a direct relationship between the Hartree-Fock (HF) kinetic-overlap (KO) approximation method and the semiempirical tight-binding (STB) method in band structure calculations. We deduce for the STB simpler two-center matrix elements than generally considered. We also suggest simple corrections to the STB matrix elements which may better describe the general case of open-shell subsystems. We argue that these corrections, which are generally ignored in all semiempirical methods, may be relevant in semiconductors and insulators with relatively low dielectric screening.