Structural properties of supercooled liquid silicon by molecular dynamics

Structural properties of supercooled liquid silicon have been investigated by large-scale molecular dynamics (MD) simulation with N = 1728 particles using the empirical Stillinger-Weber (SW) potential. The latter has been modified by taking into account measurements of the density in the stable liquid near the melting point. The description of the ionic arrangement is in excellent agreement with the recent experiments of Ansell et al. [J Phys.: Condens. Matter 10, L73 (1998)]. On the other hand, the bond-angle distribution function compares quite well the ab initio MD, indicating clearly the superimposition of reminiscent covalent bonding configurations on the Liquid-metallic phase; By the light of these experiments, our theoretical study indicates that (i) the SW potential remains a realistic empirical model for the prediction of disordered phases of silicon and (ii) the change in the structure upon supercooling is related to an increase of the density.