Structure factor and atomic dynamics of stable and supercooled liquid silicon by molecular dynamics

Abstract The structural properties and the atomic dynamics of liquid and supercooled silicon are investigated by a molecular dynamics simulation, using the empirical Stillinger–Weber (SW) potential. The description of the structure factor is in good agreement with very recent X-ray diffraction experiments, provided that the SW model is modified by taking into account new experimental results of the density in the stable liquid near the melting point. The features of the velocity autocorrelation function and the corresponding spectral density are examined. The SW potential appears to be well-designed for studying disordered phases of silicon. In particular, it allows us to investigate the process giving rise to the supercooled states, which are associated to a gradual increase of the density as confirmed by recent experiments.