High pressure melting of MgO

The high pressure melting curve of MgO is simulated by using the constant temperature and pressure molecular dynamics method combined with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction at high pressure and high temperature. It is shown that the simulated molar volume of MgO is very successful in reproducing accurately the recent experimental data over wide pressure ranges. The pressure dependence of the simulated high pressure melting temperature of MgO is in good agreement with the latest theoretical data. The simulated high pressure melting curve of MgO up to lower mantle pressure, being rather steep at lower pressures, rapidly flattens on increasing pressure. At the core–mantle boundary pressure of 135 GPa MgO melts at 7500 K, which is significantly higher than the extrapolations of the currently available experimental data derived by Zerr and Boehler.