Necessity of Large-Scaled and Non-Empirical Molecular Dynamics Simulation of Silicate Liquids at High Pressure
Necessity of Large-Scaled and Non-Empirical Molecular Dynamics Simulation of Silicate Liquids at High Pressure
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高压硅酸盐液体大规模非经验分子动力学模拟的必要性
DOI：
10.4131/jshpreview.27.198
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
F. Noritake
中科院分区：
文献类型：
--
作者：
F. Noritake
硅酸盐液体的物理性质在压力下表现出特殊的行为。随着压力的增加，酸性硅酸盐液体的剪切粘度降低，而碱性硅酸盐液体的剪切粘度增加。此外，还报道了压缩曲线上的异常现象。这些实验结果表明，硅酸盐液体在组成/压力面上具有多种特征结构。分子动力学模拟提供了模拟晶胞中所有原子的运动轨迹，是研究硅酸盐液体的静态/动态性质与压力和组成关系的合适方法。此外，第一性原理分子动力学模拟是更适合的方法，因为作用力是从电子结构计算出来的。它使我们能够模拟极端的情况，如液体中的键交换事件，而不需要经验因素。然而，强的有限尺寸效应使第一性原理分子动力学模拟不能应用，因为它需要至少由104个原子组成的体系才能获得可靠的物理性质。因此，发展线性尺度第一性原理分子动力学模拟程序对于推进硅酸盐液体的理论研究是必要的。[分子动力学，硅酸盐液体，高压，有限尺寸效应]
The physical properties of silicate liquids show peculiar behaviors under pressure. Shear viscosities of acidic silicate liquids decrease with increasing pressure although that of basic silicate liquids increase. Moreover, the anomalies in compression curves also have been reported. These experimental results indicate that the silicate liquids have several types of characteristic structure in composition/pressure plane. The molecular dynamics simulation is an appropriate method for investigating response of static/dynamic properties of the silicate liquids vs. pressure and composition because it provides the trajectories of the all atoms in simulation cell. Moreover, the firstprinciples molecular dynamics simulation is more suitable method because the forces are calculated from electronic structure. It enables us to simulate the extreme situation, such as bond exchanging event in liquid, without empirical factor. However, the strong finite size effect does not allow the application of first-principles molecular dynamics simulations because of its heavy calculation cost, because the system composed of at least 104 atoms is required in order to obtain the reliable physical properties. Consequently, the development of linear-scaling first-principles molecular dynamics simulation codes is necessary for the advance of theoretical study of silicate liquids. [molecular dynamics, silicate liquids, high pressure, finite size effect]