Computational Simulations of the Vibrational Properties of Glasses
Computational Simulations of the Vibrational Properties of Glasses
复制标题
玻璃振动特性的计算模拟
DOI：
10.1142/9781800612587_0010
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Ikeda Atsushi
中科院分区：
文献类型：
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作者：
Mizuno Hideyuki;Ikeda Atsushi
目前，计算模拟在基础科学和工程应用的发展中发挥着重要作用，这是毋庸置疑的。分子动力学(MD)模拟和蒙特卡罗(MC)模拟被用来在微观、分子水平上模拟材料在稠密的气体、液体和固体状态下的行为。1，2这些分子模拟的重要性来自这样一个事实，即它们在明确定义的材料模拟模型上提供了准确的准实验数据。模拟的有用性还基于这样一个事实，即它们可以访问无法通过实验获得的数据。从理论的角度来看，原型模型的准确数据对于理解现象的基本机制以及检验所提出的理论的有效性都是有价值的。在过去，分子模拟被用来解决许多重要的问题。例如，在统计物理中，相变，如气液相变和顺磁铁磁相变，是计算机模拟研究最广泛的课题之一。此外，为了解决玻璃化转变的问题，许多以前的工作依赖于对玻璃化转变附近急剧减慢的动力学的模拟。4、5计算模拟也是研究玻璃振动性质的有力工具。对于晶体，由于它们的周期性和对称性，可以得到分子振动运动的解析公式，这就给出了声子(晶格波)的概念。特别地，建立了德拜理论来解释晶体中振动态密度(VDOS)的行为。相比之下，对于玻璃，由于缺乏周期性和对称性，解析计算很难进行。虽然已经提出了一些平均场理论，如复制理论8和有效介质理论9-12，但它是
Currently, there is no doubt that computational simulations play an important role in the development of fundamental science as well as engineering applications. Molecular Dynamics (MD) simulations and Monte Carlo (MC) simulations have been established to simulate the behaviours of materials in dense gas, liquid, and solid states at the microscopic, molecular level. 1, 2 The importance of these molecular simulations comes from the fact that they provide exact, quasiexperimental data on well-defined simulation models of materials. The usefulness of simulations is also based on the fact that they can access data that cannot be obtained through experiments. From the theoretical point of view, exact data on prototypical models are valuable for understanding the fundamental mechanisms of phenomena as well as for testing the validity of proposed theories. In the past, molecular simulations have been employed to solve many important problems. For example, in statistical physics, phase transitions, such as the gas-liquid transition and the paramagneticferromagnetic transition, are among the topics that are most widely studied by means of computer simulations. 3 Additionally, to address the problem of glass transition, many previous works have relied on simulations of, eg, the drastically slowed dynamics near the glass transition. 4, 5Computational simulations are also a powerful tool for studying the vibrational properties of glasses. For crystals, thanks to their periodicity and symmetry, analytical formulations can be obtained for the vibrational motions of the molecules, which give the concept of phonons (lattice waves). a, 6, 7 Particularly, the Debye theory has been established to explain the behaviour of the vibrational density of states (vDOS) in a crystal. In contrast, for glasses, due to the lack of periodicity and symmetry, analytical calculations are much difficult to perform. Although some mean-field theories, such as replica theory 8 and effective medium theory, 9–12 have been proposed, it is