Green's-function method for crystal films and surfaces

Abstract

The Green's-function method is adapted to the problem of an electron moving in a crystal film. The potential is taken as spherical in the atomic spheres and as dependent only on the coordinate normal to the film in the regions just outside the bounding atom planes. The appropriate new structure constants are defined. With the aid of the necessary logarithmic derivatives a rather small set of simultaneous linear equations is obtained from which eigenvalues and eigenfunctions can be calculated. In conjunction with the density functional formalism this procedure provides a convenient method for self-consistently calculating the electronic structure of films and surfaces. Comparison with earlier work by Pharisean, Scherer, Cooper, and Beeby is made.