Parametrization of Stillinger–Weber potential based on valence force field model: application to single-layer MoS2 and black phosphorus.

We propose parametrizing the Stillinger–Weber potential for covalent materials starting from the valence force-field model. All geometrical parameters in the Stillinger–Weber potential are determined analytically according to the equilibrium condition for each individual potential term, while the energy parameters are derived from the valence force-field model. This parametrization approach transfers the accuracy of the valence force field model to the Stillinger–Weber potential. Furthermore, the resulting Stilliinger–Weber potential supports stable molecular dynamics simulations, as each potential term is at an energy-minimum state separately at the equilibrium configuration. We employ this procedure to parametrize Stillinger–Weber potentials for single-layer MoS2 and black phosphorous. The obtained Stillinger–Weber potentials predict an accurate phonon spectrum and mechanical behaviors. We also provide input scripts of these Stillinger–Weber potentials used by publicly available simulation packages including GULP and LAMMPS. [ABSTRACT FROM AUTHOR]