Abstract
We have developed a semi-empirical perturbation scheme for the purpose of relating the energy band structures of diamond-type and zinc-blende-type crystals. Our sole objective is to predict the approximate location of the valence and conduction band edges in the reduced zone for some of the better known zinc-blende-type crystals. In this paper we explain how the perturbation scheme operates. Since a more complete account will appear in The Physical Review (Herman 1955), we will restrict ourselves here only to the essentials. A brief discussion of the effect of the spin-orbit interaction upon the band structure of zinc-blende-type crystals is also included in the present paper.