Prediction of melting curves of ionic and partially covalent compounds using the Jeanloz equation for the Grüneisen parameter

We have predicted melting temperatures of ionic and partially covalent compounds viz. NaCl, NaF, LiF, MgO, CaF₂, SiC at high pressures. The volume dependence of Grüneisen parameter determined from the Jeanloz equation has been used in the Lindemann law to predict melting curves. The pressure–volume relationships used in computations are determined with the help of the Holzapfel equation of state based on the adapted polynomial expansion of second order. The results for melting curves of different solids obtained in the present study using \({\upgamma }_{\infty }=1/2\) ${\mathrm{\gamma }}_{\infty }=1/2$ at extreme compression are found to be in reasonably good agreement with the available experimental data. We have also calculated slopes of melting curves at different pressures for the six compounds under study. It is found that the melting slopes decrease continuously with the increase in pressure, and tend to zero in the limit of infinite pressure. The results obtained in the present study are found to compare well with the experimental data and molecular dynamics simulations.