有限温度字符串由K-意味着用顺序参数作为分子晶体的集体变量进行集群采样:应用于β-CL-20和ε-CL-20之间的多态转换
Fu-de Ren1, Ying-Zhe Liu2, Ke-Wei Ding2
1School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China. fdren888@126.com.
Physical chemistry chemical physics : PCCP
|January 11, 2024
概括
了解分子晶体的多态转换是工业的关键. 这项研究揭示了CL-20的表面介导核化机制,改善了复杂相变的模拟方法.
科学领域:
- 分子固态化学分子固态化学
- 计算材料科学科学 计算材料科学
背景情况:
- 分子晶体中的多态转化对各种行业至关重要,但在分子层面上了解得很少.
- 模拟这些转换是具有挑战性的,因为对复杂结构的增强采样和定义顺序参数 (OPs) 存在困难.
研究的目的:
- 阐明 β-CL-20 和 ε-CL-20 之间的多态转换的分子层次机制.
- 开发和应用有效的计算方法来研究中的分子晶体中的相位过渡.
主要方法:
- 使用债券距离,债券方向和相对方向构建了两种类型的订单参数 (OP).
- 采用K-means集群算法来改进有限温度字符串 (FTS) 以提高收.
- 在集体变量,马可维里程碑和沃罗诺伊模块中使用了弦方法来确定最小的自由能量路径和核化动力学.
主要成果:
- 与基于平均值的采样相比,K-means集群算法证明了FTS的更快的收率.
- 模拟表明,转换受到有限大小的影响,但独立于使用的特定OP类型.
- 证实了表面介导的局部核化机制,确定了平均力潜力的肩膀上的关键核.
结论:
- 这项研究提供了一种有效的计算方法,用于探索子分子晶体中的多态转换.
- 这些发现突出了表面介导的核化机制,以及分子间相互作用在关键核形成中的重要性.
- 这项工作促进了对晶体材料中的分子级相变的理解.
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