Theory of materials under extreme conditions

在高压、高温、应变电场和磁场的极端环境中工作的材料对于提供安全、经济和可靠能源的各种技术至关重要。例子包括高能量密度材料的合成，核裂变和聚变反应堆，以及废物管理。 极端条件下的材料知识也具有基本的科学重要性，对于了解行星的形成、地球的物理和化学及其气候至关重要。 我们研究的主要重点是通过理论从头算方法研究高压和/或高温条件下的系统。 从头算模拟是一种方法，其中描述材料微观特性的量子力学基本方程在不需要实验输入的情况下进行数值求解。该计划的科学目标包括：（一）使用压力作为合成新型高能材料的独特工具;（二）回答在超压下化学键合的存在和性质的基本问题;以及（三）预测与行星科学相关的系统的热力学和结构特性。 关于上述科学目标，研究计划有几个技术目标。其中包括为以下目的开发计算框架：㈠快速预测高压下有限温度结构稳定性; ㈡有效计算液体和高温固体自由能; ㈢精确模拟极端压缩下的材料; ㈣模拟不同环境和现实时间和长度尺度下的质量输运过程。

Materials that perform in extreme environments of high pressure, temperature, strain electric, and magnetic field are essential to a diverse range of technologies that provide safe, economic, and reliable energy. Examples include the synthesis of high energy density materials, nuclear fission and fusion reactors, and waste management. The knowledge of materials under extreme conditions is also of fundamental scientific importance and crucial for understanding planetary formation, and the physics and chemistry of the earth and its climate. The main focus of our research is the study of systems at high pressure and/or temperature conditions by means of theoretical ab initio methods. Ab initio simulation is an approach where the fundamental equations of quantum mechanics, describing the microscopic properties of materials, are solved numerically without the need for input from experiment. The scientific objectives of the program include: (i) using pressure as a unique tool for the synthesis of novel energetic materials; (ii) answering the fundamental question for the existence and nature of chemical bonding at ultrahigh compression; and (iii) predicting the thermodynamic and structural properties of systems relevant to planetary science. In relation to the above scientific goals, the research program has several technical objectives. These includes the development of computational frameworks for: (i) rapid prediction of finite-temperature structural stability at high pressure; (ii) efficient calculations of liquid and high-temperature-solid free energies; (iii) accurate simulation of materials at extreme compression; and (iv) simulations of mass transport processes in diverse environments and realistic time and length scales.