Effects of high-pressure environments on atomic dynamics in disordered materials with covalent bonds

基于第一性原理分子动力学模拟和中子和x射线非弹性散射实验技术的理论计算，阐明了各种共价液体（如典型的液态二氧化硅）中原子扩散的微观机制及其压力依赖性。我们研究了不同压力下局部原子结构和原子间键合性质的时间演化，并从动力学不对称的角度讨论了压力下共价液体的原子动力学。本研究获得的知识对于理解诸如二氧化硅和水等在地球物理学和生物学等许多领域受到关注的材料的动力学性质具有重要意义。

The microscopic mechanisms of atomic diffusion and their pressure dependence in various covalent liquids, such as typically liquid silica, have been clarified by theoretical calculations based on first-principles molecular-dynamics simulations and experimental techniques of neutron and x-ray inelastic scattering. We investigated the time evolution of local atomic structure and bonding properties between atoms at each pressure, and discussed atomic dynamics in covalent liquids under pressure from a point of view of dynamic asymmetry. The knowledge obtained in this study is important in understanding dynamic properties of materials, such as silica and water, which are getting attention in many fields including geophysics and biology.