Collaborative Research: Quantum Mechanical Modeling of Major Mantle Materials

合作研究：主要地幔材料的量子力学模拟

• 批准号: 0230154
• 负责人: Lars Stixrude
• 金额: $ 38.15万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0230154&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantum; Mechanical; Modeling

EAR-0230154Lars StixrudeTranslating the record of deep-seated geological processes as revealed by seismic structure or xenoliths requires sophisticated knowledge of the essential physics, chemistry, and atomic scale structure of minerals at high pressures and temperatures. Over the course of their prior collaborative project, the investigators have developed a new approach to the study of mantle materials based on density functional theory that is complementary to experimental efforts in mineral physics. They have shown that theory can provide insights into the fundamentals of material behavior that form the basis of our ability to interpolate among and extrapolate from necessarily limited experimental or theoretical results to a complex earth. The investigators past studies of pure end-member phases have predicted properties that have lent important new insight into the nature of the earth's interior. In this proposal, they move toward considering the interaction between mantle minerals through phase transitions and chemical exchange.This research will pursue for the first time with ab initio methods the theoretical investigation of mantle solid solutions, including their structure, thermochemistry, and physical properties, and of phase equilibria,. The investigators will also continue with established directions including the prediction of thermoelastic properties. This research is expected to contribute to our understanding of: 1) The origins of lateral heterogeneity in the mantle, through predictions of the effects of temperature and composition on the elastic properties of solid solutions, including Mg-Ca-Al-Fe perovskite at lower mantle conditions. 2) The origin, structure, and geodynamical consequences of seismic "discontinuities", through predictions of one-component and multi-component phase equilibria including the akimotoite to perovskite transition, and the pseudobinary ringwoodite to perovskite plus magnesiowustite transition. 3) The interpretation of samples of possible transition zone and lower mantle origin, through predictions of phase equilibira and element partitioning among major coexisting phases, including Mg-Ca partitioning and exsolution in silicate perovskite.

EAR-0230154LARS stixRudEtranslanslanslanslans逐渐阐明了地震结构或异种石的深层地质过程记录，需要对高压和温度下矿物质的必要物理学，化学和原子规模结构进行复杂的了解。在他们先前的合作项目中，研究人员开发了一种基于密度功能理论的地幔材料研究的新方法，该方法与矿物质物理学的实验努力相辅相成。他们表明，理论可以提供对材料行为的基础知识的见解，这些基本面是我们在相互插入并从一定有限的实验或理论结果推断到复杂地球的能力的基础。研究人员过去对纯最终成员阶段的研究预测了对地球内部本质的重要新见解。在该提案中，他们朝着通过相变和化学交换来考虑地幔矿物质之间的相互作用。这项研究将首次通过从头算方法进行地幔固体溶液的理论研究，包括其结构，热化学和物理性质，以及相位平衡的结构。 研究人员还将继续采用既定方向，包括预测热弹性性能。预计这项研究将有助于我们对：1）地幔中侧向异质性的起源，通过预测温度和成分对固体溶液弹性性能的影响，包括在较低地幔条件下MG-CA-FE钙钛矿。 2）通过预测一个组分和多组分相位平衡，包括阿基莫替石到钙钛矿过渡，以及pseudobinary ringwoodite to Perovskite Plus MagnesioWustite Transition，通过预测一个组分和多组分相位平衡，来源，结构和地震动力学后果。 3）通过对主要共存阶段之间的相位平衡和元素分配的预测，包括MG-CA分配和硅酸盐钙钛矿中的实质性分配的解释，对可能的过渡区和较低地幔起源的样品进行解释。