Quantum Mechanical Modeling of Major Mantle Materials

主要地幔材料的量子力学模拟

• 批准号: 1019853
• 负责人: Renata Wentzcovitch
• 金额: $ 74.2万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1019853&HistoricalAwards=false
• 关键词: Quantum; Mechanical; Modeling; Major; Mantle

In the last decade, computational mineral physics has played a fundamental role in our understanding of the Earth. It has complemented experiments by expanding the range of thermodynamics conditions materials properties can be investigated and has provided new insights into the nature of Earth's interior based on atomic scale arguments. This project supports a continuation of studies that use first principles calculations to quantify fundamental chemical and physical properties of some common minerals present deep in the interior of the Earth.Under this grant it is proposed to expand first principles studies of Earth's materials to i) include anharmonic effects on calculations of thermal properties and phase relations of minerals using methods recently developed by the team; ii) advance studies of phase transformations in solid solutions, particularly for the post-perovskite transition; iii) explore the rheological consequences of the spin-state crossover in ferropericlase, the second most important phase in the lower mantle; iv) couple these studies with geodynamical modeling of the mantle. These studies will make key contributions to our understanding of i) thermodynamic equilibrium in multi-phase aggregates; ii) properties of thermodynamics phase boundaries of major mantle minerals. There are still large uncertainties associated with measurements of Clapeyron slopes, discontinuities, and two-phase loops in divariant systems. These quantities control mantle dynamics and will be better constrained; iii) the rheology of ferropericlase has been implicated in the proposed viscosity minimum around 1,600 km depth and will now be investigated; iv) the geodynamical sensitivity to and consequences of these results. This research, which has intrinsic interdisciplinary value, will shed light on the nature and dynamics in the D" and mid-lower mantle regions.

在过去的十年中，计算矿物物理学在我们对地球的理解中发挥了重要作用。它补充了实验，扩大了可以研究材料特性的热力学条件的范围，并根据原子尺度的论点对地球内部的性质提供了新的见解。该项目支持继续进行利用第一性原理计算来量化地球内部深处存在的一些常见矿物的基本化学和物理性质的研究。在该资助下，建议扩大地球材料的第一性原理研究，以i）包括利用该小组最近开发的方法计算矿物的热性质和相关系的非谐效应; ii）推进固溶体相变的研究，特别是后钙钛矿转变; iii）探索铁方镁石中自旋态交叉的流变学后果，铁方镁石是下地幔中第二个最重要的相; iv）将这些研究与地幔的地球动力学建模相结合。这些研究将为我们理解多相聚集体的热力学平衡和地幔主要矿物的热力学相边界性质做出重要贡献。仍然有很大的不确定性与测量克拉珀龙斜率，不连续性，和两相回路在双变系统。这些数量控制地幔动力学，将更好地约束; iii）铁方镁石的流变学已牵连在拟议的粘度最低约1,600公里的深度，现在将进行调查; iv）地球动力学的敏感性和这些结果的后果。该研究具有内在的跨学科价值，将有助于揭示D”和中下地幔区的性质和动力学。