新的相互作用势对MD模拟钙钛矿结构MgSiO3热力学性质的影响

通过分析势能曲线解释了钙钛矿结构MgSiO3熔化模拟过程中模拟熔化温度存在较大差异的原因，并进一步研究了对势参数在分子动力学模拟中的影响. 通过调整已有的经验势得到了一组新的势参数，以此来进行分子动力学研究，得到的常温常压下摩尔体积与Belonoshko和Dubrovinsky的结果符合较好，并且其状态方程、常压下热容和常压下热膨胀系数与他人的实验值都较好地吻合. 另外，所得到的熔化温度也与以前的研究进行了比较.

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 potential has been used to simulate the melting temperature of MgSiO3 perovskite in previous studies, but considerable discrepancy of melting temperature exists between these simulations. Comparisons of potential energy curves are performed to explain the discrepancy. To further investigate the infuence of the interaction potential parameters 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.