稠密轻质物质中原子核量子交换效应的分子动力学研究

项目名称： 稠密轻质物质中原子核量子交换效应的分子动力学研究

项目编号： No.11504422

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 康冬冬

作者单位： 中国人民解放军国防科技大学

项目金额： 20万元

中文摘要： 温稠密物质的结构和动力学性质在天体物理、地球和行星科学以及惯性约束核聚变领域具有重要的科学意义和巨大的应用价值。本项目以氢、氦等轻质原子组成的稠密轻质物质为研究对象，基于统计力学配分函数的路径积分表述形式，利用高阶Trotter分裂算符方法和高效的交换赝势计算方法，发展包含原子核量子交换效应以及空间非局域效应的路径积分分子动力学方法，并结合计算电子结构的密度泛函理论，实现对温稠密物质的“全量子模拟”。利用该方法，系统地研究稠密轻质物质的结构和动力学性质，阐明其随温度和压强变化的一般规律，揭示极端条件下物质结构中原子分子的量子动力学行为机制，深入理解原子核的量子交换效应对稠密氢的金属化转变、结构相变、熔化行为以及光电性质的影响。本项目可为极端条件下物质结构的实验研究提供理论依据。

中文关键词： 温稠密物质；相变；分子间相互作用；分子结构的压力效应；分子解离

英文摘要： Structure and dynamical properties of warm dense matter (WDM) is not only of fundamental significance in physics, but also crucial to application fields involving astrophysics, geophysics, planetary science and inertial confinement fusion. This project chooses dense light-atom matter such as hydrogen and helium as the object of research. We firstly use the high-order Trotter operator-splitting to discretize the partition function in path-integral formalism, and calculate the exchange pseudopotential based on efficient algorithm for Fermi and Bose systems. Finally, the path-integral molecular dynamics (PIMD) method including nuclear quantum exchange effect and delocalization effect is constructed. The calculation method for electronic properties based on density functional theory is combined with the PIMD approach, which realizes the “all-quantum simulation” for WDM. Using this approach, the structure and dynamical properties of dense light-atom matter are systematically investigated and the universal rules of these properties as a function of temperature and density are clearly elucidated. We reveal the physical mechanism of the quantum dynamics of atoms and molecules under extreme conditions, and thoroughly understand the nuclear quantum exchange effect on the metallization, phase transition, melting and optical properties of dense hydrogen. This project can provide theoretical foundation for experimental investigation of matter under extreme conditions.

英文关键词： warm dense matter;phase transition;intermolecular interaction;pressure effect of molecular structure;molecular dissociation