Comparison of threshold displacement energies in β-SiC determined by classical potentials and ab initio calculations

Abstract

Using classical molecular dynamics and ab initio calculations, we have determined threshold displacement energies in cubic silicon carbide, in order to understand the large disparity of values available in literature. First, we checked the influence of simulation parameters such as the box size and the temperature control. Then, we compared empirical potentials and ab initio methods, within the sudden approximation (SA). Our results clearly show that the use of available empirical potentials is the largest source of errors, and call for the improvement of existing potentials or the determination of threshold displacement energies by ab initio molecular dynamics.