Collaborative Research: Quantum Mechanical Modeling of Major Mantle Materials

研究人员继续在地幔物质的第一性原理研究中看到一个不断扩大的发现前沿。在最后一次更新中，该团队提出了一个重大的新扩展，他们的研究范围从研究单个地幔相的物理性质，到通过相变和化学交换了解它们之间的相互作用。将研究重点从矿物学扩展到岩石学是非常成功的，这对于进一步了解地幔结构的起源、组成和演化是至关重要的。pi现在提出了在第一原理方法应用于地幔材料领域的重大进展。这项建议是建立在过去成功的坚实基础之上的：他们已经开发了实现这些目标所需的所有工具，并已经在所有领域取得了令人鼓舞的成果。研究人员期望他们的研究将对理解地幔横向非均质性的起源做出关键贡献：1)通过研究固溶体的物理性质，包括铁中高自旋到低自旋转变的影响。2)通过预测共存的地幔相（包括顽辉石-刚玉连接和MgO-FeO-SiO2体系）的相平衡和元素分配，解释可能的下地幔起源样品。3)通过预测氢在名义上无水相中的溶解度、研究含水相的稳定性和预测电导率来计算地幔中的水量。对年轻科学家的指导将继续成为这项研究更广泛影响的重要组成部分，包括对研究小组内的学生和博士后的培训，以及由VLab（地球和行星材料虚拟实验室）和CIDER（深地研究合作研究所）促进的更广泛的教育。

The investigators continue to see an ever-widening frontier of discovery in the first principles study of mantle materials. In their last renewal, the team proposed a major new expansion in the scope of their research from the study of the physical properties of individual mantle phases, towards an understanding of the interaction among them through phase transitions and chemical exchange. This widening of focus from the mineralogical towards the petrological has been very successful, and has been essential for continuing progress in understanding the origin of mantle structure, its composition, and evolution.The PIs now propose significant advances in the realm of application of first principles methods to mantle materials. This proposal is based on the firm foundations of past success: they have developed all the tools that are needed to accomplish these goals, and have already obtained encouraging results in all areas. The investigators expect that their research will make key contributions to understanding: 1) The origins of lateral heterogeneity in the mantle, through investigations of the physical properties of solid solutions, including the influence of the high-spin to low-spin transition in iron. 2) The interpretation of samples of possible lower mantle origin, via predictions of phase equilibria and element partitioning among coexisting mantle phases including those on the enstatite-corundum join and in the MgO-FeO-SiO2 system. 3) The amount of water in Earth's mantle, through predictions of hydrogen solubility in nominally anhydrous phases, investigations of the stability of hydrous phases, and predictions of electrical conductivity. Mentoring of young scientists will continue to be an important part of the broader impacts of this research, including training of students and post-docs within the research groups and broader education facilitated by VLab, the Virtual Laboratory for Earth and planetary materials, and CIDER, the Cooperative Institute for Deep Earth Research.