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了解地球方面发挥了基础性作用。它通过扩大可以研究材料特性的热力学条件范围来补充实验，并基于原子尺度的论证为地球内部的性质提供了新的见解。该项目支持继续进行研究，利用第一原理计算来量化地球内部深处一些常见矿物的基本化学和物理性质。根据这项拨款，建议将地球材料的第一原理研究扩展到i) 包括使用该团队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) 推进固溶体中相变的研究，特别是后钙钛矿相变； iii) 探索方镁石中自旋态交叉的流变学后果，方镁石是下地幔中第二重要的相； iv) 将这些研究与地幔地球动力学模型结合起来。这些研究将为我们理解 i) 多相聚集体的热力学平衡做出重要贡献； ii）主要地幔矿物的热力学相界性质。与异变系统中的克拉佩龙斜率、不连续性和两相环路的测量仍然存在很大的不确定性。这些量控制着地幔动力学，并将受到更好的约束； iii) 方镁石的流变性与建议的 1,600 公里深度附近的粘度最小值有关，现在将进行研究； iv) 这些结果的地球动力学敏感性及其后果。这项研究具有内在的跨学科价值，将揭示D"和中下地幔区域的性质和动态。