Theory of dynamical stability for two- and three-dimensional Lennard-Jones crystals
Theory of dynamical stability for two- and three-dimensional Lennard-Jones crystals
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二维和三维 Lennard-Jones 晶体的动态稳定性理论
DOI：
10.1103/physrevb.103.075406
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Tasuku Ito
中科院分区：
文献类型：
--
作者：
S. Ono;Tasuku Ito
三维（3D） Lennard-Jones （LJ）晶体的动力学稳定性已被研究多年。fcc和hcp结构是动态稳定的，而bcc结构只有在以相对较小的整数对$(m,n)$为特征的远程LJ势时才稳定。在这里，我们研究二维LJ晶体的动力学稳定性，其中假设平面六边形，屈曲蜂窝结构和屈曲方形结构。我们证明了二维和三维LJ晶体的稳定性可以根据$(m,n)$分为四类。在解析表达式中研究了平面六边形、屈曲方形和bcc结构的不稳定性。讨论了LJ晶体与元素周期表中元素之间的结构-稳定性关系。
The dynamical stability of three-dimensional (3D) Lennard-Jones (LJ) crystals has been studied for many years. The fcc and hcp structures are dynamically stable, while the bcc structure is stable only for long-range LJ potentials that are characterized by relatively small integer pairs $(m,n)$. Here, we study the dynamical stability of two-dimensional (2D) LJ crystals, where the planar hexagonal, the buckled honeycomb, and the buckled square structures are assumed. We demonstrate that the stability property of 2D and 3D LJ crystals can be classified into four groups depending on $(m,n)$. The instabilities of the planar hexagonal, the buckled square, and the bcc structures are investigated within analytical expressions. The structure-stability relationship between the LJ crystals and the elemental metals in the periodic table is also discussed.