Collaborative Research: Quantum Mechanical Modeling of Major Mantle Materials

研究人员继续看到，在地幔物质的第一原理研究中，发现的前沿正在不断扩大。在最近一次更新中，该小组提议对其研究范围进行新的重大扩展，从研究单个地幔阶段的物理性质，转向通过相变和化学交换了解它们之间的相互作用。这种从矿物学向岩石学的扩展是非常成功的，对于继续了解地幔结构的起源、组成和演化是必不可少的。目前，PI在第一性原理方法在地幔材料应用领域提出了重大进展。这项建议是建立在过去成功的坚实基础上的：它们开发了实现这些目标所需的所有工具，并在所有领域都取得了令人鼓舞的成果。研究人员预计，他们的研究将对理解以下问题做出关键贡献：1)通过研究固溶体的物理性质，包括铁从高自旋到低自旋转变的影响，了解地幔横向不均匀的起源。2)通过预测共存地幔相之间的相平衡和元素分配，解释可能来自下地幔的样品，包括顽火辉石-刚玉接合部和MgO-FeO-SiO_2系中的地幔相。3)通过预测氢气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。对青年科学家的指导将继续是这项研究更广泛影响的重要组成部分，包括在研究小组内培训学生和博士后，以及由VLAB(地球和行星材料虚拟实验室)和苹果酒(地球深部研究合作研究所)推动的更广泛的教育。

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.