Modeling Liquid Antimony by Means of Molecular Dynamics

The potential of the embedded-atom model (EAM) for liquid antimony is calculated, and the molecular dynamics models are constructed for antimony at temperatures of up to 2023 K and under conditions of shock compression up to a pressure of 131 GPa. It is established that the EAM potential describes the behavior of the shoulder of pair correlation function (PCF). Good agreement with the experimental data is obtained for the structure and density of the liquid, the speed of sound at the binodal, and discrepancies are obtained with the experimental data for the energy. It is found that the self-diffusion coefficient is overstated near the melting point, but the discrepancy disappears upon heating; the calculated shock adiabat agrees with the experimental results; and the structure of liquid antimony models at pressures up to 8 GPa is not consistent with the diffraction data regarding the shape of the first PCF peak. It is concluded that the structural features of the anomalous metal (antimony) are determined by an existence of the interval to the right of the first PCF peak, at which the curvature of the interparticle potential is negative.