Melting line of Yukawa system by computer simulation

We located the melting line of the Yukawa system by determining the free energy of both fluid and solid phases by computer simulations. At the high densities the fluid freezes into a body-centered-cubic (bcc) solid, whereas for low densities it freezes into a face-centered-cubic (fcc) solid. For both the bcc-fluid and the fcc-fluid part of the melting line two coexistence points were determined. We observed that the relative root-mean-square displacement in the solid (Lindeman ratio) varies considerably along the melting line. At the bcc-fluid part of the melting line the Lindeman ratio equals 0.19, whereas at the fcc-solid part of the melting line it is smaller than 0.16.