Interplanar force constants in GaAs and Ge: Bond-Charge-Model vs. ab-initio calculations

Abstract

Recent Bond-Charge-Model calculations of interplanar force constants for Si and Ge by A. Fleszar and R. Resta have provided an interesting comparison between ab initio and fitted force constants along [001] and [111] directions. Our extensions to polar GaAs and to the [110] direction provide a guideline for ab initio calculations and supply an helpful comparison between different directions for the study of semiconductor superlattice dynamics.