ABSTRACT
Approximate band structure calculation methods, therefore, have often been developed in order to minimize the computational demand and the computational time required in meeting such demands. This chapter describes the tight binding model for crystal systems with one electron per atom. It obtains the site Green’s function, show its relationship with the k-space Green’s function, and also relate it to the density of states. The chapter presents the method the authors use to perform the numerical integration singular function integration. The total density of states, N(E), shows that the band is filled with one state when the energy reaches the band width and if the authors include spin, two electrons occupy the entire band. The chapter works with a multiband system which arises from the interactions between the valence electrons in the s and p orbitals. Aside from the expected differences, the shapes of the curves do bear resemblance, which makes the eight-band model instructive.
