ONE-PARTICLE ENERGY SPECTRUM OF AN ELECTRON SYSTEM IN A PERIODIC FIELD

Abstract

The energy spectrum of an electron in the vicinity of the Fermi surface of an electron system in a periodic field is determined approximately by applying the generalized self-consistent field method of Cohen. The main approximation involved may be regarded as an extension of the random phase approximation usually applied to the interelectronic interaction of an electron gas, to the case including a periodic field. The effect of the periodic field is treated by a secondorder perturbation.The result is expressed as[Formula: see text]The correction terms are roughly estimated numerically and are shown to be small for a simple model of a metal, metallic hydrogen. A brief discussion of the extension of the approximation is given.