CSEDI: Theoretical and Experimental Studies of Some Materials Fundamental to the Deep Mantle

Duffy 0112532研究人员将开发新的理论技术，并进行新的高压和高温实验，以检查以下材料的熔化曲线，晶体结构和高温状态方程（EOS）：MgO，SiO2，MgSiO 3和Au。 他们将通过开发密度泛函理论的主要扩展-分子动力学（DFT-MD）方法并将其应用于地球深部地幔的矿物来实现这一目标。 该方法是从DFT-MD模拟的结果开发经验“最佳”潜力。 这种最佳的潜力，然后可以用于进一步的计算，涉及更大的系统和更长的运行时间。 由此，研究人员可以直接在下地幔P-T条件下确定晶体结构、熔化曲线、液体粘度、压缩系数、弹性常数和其他热弹性性质。他们还将对模拟结果与MgO、SiO2和Au的激光加热同步加速器实验进行详细比较，以评估OP方法的可靠性。特别是，他们将专注于测量这些材料在高压下的熔化曲线，以提供最佳电位计算的敏感测试。

Duffy 0112532 The investigators will develop new theoretical techniques and conduct new high pressure and temperature experiments to examine the melting curves, crystal structures, and high-temperature equations of state (EOS) of the following materials: MgO, SiO2, MgSiO3, and Au. They will accomplish this by developing a major extension of the density functional theory - molecular dynamics (DFT-MD) method and applying it to minerals of the Earth's deep mantle. The approach is to develop empirical "optimal" potentials from the results of a DFT-MD simulation. This optimal potential can then be used in further calculations involving much larger systems and longer run durations. From this, the investigators can determine crystal structures, melting curves, liquid viscosities, compressibilities, elastic constants and other thermoelastic properties directly at lower mantle P-T conditions. They will also carry out detailed comparison of their simulation results with laser-heated synchrotron experiments on MgO, SiO2, and Au to assess the reliability of the OP method. In particular, they will focus on measurements of melting curves of these materials at high pressure to provide a sensitive test of the optimal potential calculations.