在局部结构变化方面,超临界水中的宽度线:理论视角
Artem Shagurin1,2,3, Francois A Miannay1, Michael G Kiselev3
1University of Lille, CNRS UMR 8516 -LASIRe - Laboratoire Avancé de Spectroscopie pour les Interactions la Réactivité et l'environnement, 59000 Lille, France.
The journal of physical chemistry letters
|May 24, 2024
概括
研究人员使用分子动力学模拟在水中识别了基于结构的Widom线. 结构性质变化的极端点在这些线上,与实验热力学数据保持一致.
科学领域:
- 物理化学 物理化学
- 计算物理 计算物理
- 材料科学 材料科学 材料科学
背景情况:
- 宽度线对于理解液相行为和相位过渡至关重要.
- 传统的Widom线通过热力学响应函数来识别.
- 根据结构性质定义Widom线提供了一个互补的方法.
研究的目的:
- 定义纯粹基于结构的水的Widom线.
- 为了研究结构性质和Widom线之间的关系.
- 根据实验热力学数据对基于结构的Widom线进行验证.
主要方法:
- 在9个同位体 (175-375 bar) 和温度 (300-1100 K) 上进行TIP4P/2005水的分子动力学模拟.
- 使用四面体性,最近邻居距离,局部密度和最大密度域大小等参数分析局部水结构.
- 使用Voronoi多面体和基于密度的空间聚类来进行结构分析.
主要成果:
- 特定结构性质变化速率的极端位置定义了基于结构的Widom线.
- 在特定温度下分析分布时刻 (波动,变化速率,斜率) 可以明确地确定Widom线.
- 已识别的基于结构的Widom线与实验确定的基于热力学反应功能的Widom线一致.
结论:
- 纯粹基于结构的Widom线可以使用分子动力学模拟可靠地定义.
- 结构描述器提供了一种可靠的方法来识别水中的相位过渡前体.
- 这种方法为了解液态水的行为及其相位图提供了新的视角.
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