Shell-model interpolation of frozen phonons in cubic silicon carbide

Abstract

We present results of ab initio calculations based on the density-functional method and using the norm-conserving pseudopotentials for the phonon frequencies and eigenvectors at the L point in cubic SiC. A shell model using, for the first time, as input the eigendisplacements at both X and L points, in addition to all the available experimental phonon frequencies and elastic constants, is constructed. This description of SiC fits into the existing uniform set of valence overlap shell models for III-V and II-VI compounds.