Infuence of New Interaction Potential on MD Simulation of MgSiO3 Perovskite Thermodynamic Properties

The interaction potential plays an important role in molecular dynamics (MD) simulations. Pair potentialhas been used to simulate the melting temperature of MgSiO3 perovskite in previous studies, but considerablediscrepancy of melting temperature exists between these simulations. Comparisons of potential energy curvesare performed to explain the discrepancy. To further investigate the infuence of the interaction potentialparameters on the MD simulation result, a new set of potential parameters is developed based on two fitting potential parameters of previous studies, and is applied in the present study. The simulated molar volume MgSiO3 perovskite agrees well with the study by Belonoshko and Dubrovinsky at ambient condition. The equations of state, constant-pressure heating capacity and the constant-pressure thermal expansivity of MgSiO3 perovskite are close to the experimental data. Calculated melting temperatures are also comparable with those derived from previous studies.