Analysis of the mixing rules for the Stillinger–Weber potential: a case-study of Ge–Si interactions in the liquid phase

A liquid Ge0.25Si0.75 alloy was simulated by means of the molecular dynamics method, using the Stillinger–Weber potential. The influence of precise parametrization of the three-body term in the unlike-species interactions on the alloy structure was studied and found to be significant. Differences in the parameters of only a few percent have led to marked changes in the pair correlation functions, angular distribution functions and diffusion coefficients. A separation of the system into Ge- and Si-rich regions was observed for two parametrizations, while it was absent for the other three.