Application of empirical interatomic potentials to liquid Si

Structural and dynamical properties of liquid Si (l-Si) have been investigated by molecular-dynamics calculations using the Tersoff potential. The pair-correlation function g(r), bond-angle distribution function g({θ}), and velocity autocorrelation function Z(t) were calculated and compared with those of l-Si generated by the Stillinger-Weber (SW) potential and ab initio calculations reported previously. The Tersoff liquid reproduces g(r) obtained by the SW potential and ab initio calculations except for a slight quantitative difference. On the other hand, g({θ}) of the Tersoff liquid is entirely different from that of the SW liquid, but it is similar to the result of the ab initio approach. These results suggest that the Tersoff potential describes the features of static structures of l-Si, though this potential overestimates greatly the melting point. The Tersoff potential yields a similar tendency to the dynamical properties obtained by ab initio simulation, but some discrepancies exist, e.g., the period of oscillation in Z(t). {} 1996 The American Physical Society.