Comparison between classical potentials and ab initio methods for silicon under largeshear

Abstract

The homogeneous shear of the {111} planes along the direction of bulk silicon has been investigated using ab initio techniques, to betterunderstand the strain properties of both shuffle and glide set planes. Similar calculationshave been done with three empirical potentials, Stillinger–Weber, Tersoff and EDIP, inorder to find the one giving the best results under large shear strains. The generalizedstacking fault energies have also been calculated with these potentials to complement thisstudy. It turns out that the Stillinger–Weber potential better reproduces the ab initioresults, for the smoothness and the amplitude of the energy variation as well as thelocalization of shear in the shuffle set.