Interatomic and intra-atomic electron correlation in narrow band solids

Abstract

Effect of interatomic electron correlation has been studied in narrow band solids using one-particle Green function method. We follow Hubbard in drawing an analogy with an alloy and find a self-consistent solution which predicts a finite lifetime for pseudoparticles. A specific case of a (non-magnetic) model system with half-filled parabolic band has been considered to calculate the pseudoparticle density of states function. Unlike the result in the presence of intra-atomic correlations alone, we find that this particular system is never an insulator, however large intra-atomic correlations may be.