First-principles calculation of the melting curve and Hugoniot of tin

Abstract

By performing extensive first-principles and classical molecular-dynamics (MD) simulations, we have calculated the melting curve of tin, up to 50 GPa by direct phase coexistence, and its Hugoniot curve up to 200 GPa, using an equilibrium MD technique, the so-called Hugoniostat. In both cases, our results are in good agreement with recent shock-wave experiments, but indicate that the temperatures on the Hugoniot at very high pressures might be higher than previously thought. We also predict that the shoulder on the first peak of the liquid structure factor disappears under pressure, in connection with structural changes in the liquid.