Cluster-extended Green's function for electronic structure of localized defects in solids

Abstract

Calculations of the electronic structure of localized defects in solids are often carried out with the use of the Green's function of the perfect crystal. It is known that the Green's function employed must be complete enough to represent adequately both the perturbed and the unperturbed solid. This paper describes a simple and efficient scheme, based on the use of two sets of localized orbits, to achieve this goal. A calculation of the silicon tetrahedral self-interstitial is used to demonstrate the validity of the method and to test the effect of the single approximation introduced.