Optical properties of diamond and silicon from a tight-binding model, with local microscopic fields included

Abstract

A tight-binding Hamiltonian in a bonding-antibonding basis is used to evaluate the optical dielectric response, within the random phase approximation, for diamond and silicon. The authors include the effects of local microscopic fields, and compare the results with experiment. They also discuss theoretically how local fields should affect the optical response, and why the next term beyond the random phase approximation gives only a negligible contribution to the response.