液态水中的三体"交换"相互作用有多远?
Ommair Ishaque1, John W Melkumov1,2, Krzysztof Szalewicz1
1Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, United States.
Journal of chemical theory and computation
|March 12, 2026
概括
远程三体交换相互作用显著影响液态水密度,但不影响其他特性. 包括这些影响改善了水模型,特别是在取决于温度的密度计算.
科学领域:
- 计算化学是一种计算化学.
- 物理化学 物理化学
- 分子建模分子建模
背景情况:
- 三体相互作用对于精确的水模型至关重要,包括极化和交换术语.
- 交换互动是复杂的,由于计算成本 (N^3缩放) 和拟合挑战,往往会被减弱或截断.
- 当前的模型经常简化或省略远程三体交换效应.
研究的目的:
- 为了研究远程三体交换相互作用对水模拟的影响.
- 为了确定水的哪些特性对这些特定相互作用敏感.
- 为了解理论和实验水密度数据之间的差异提供见解.
主要方法:
- 在模拟中系统地扩展所包含的trimers的平均分子间分离 (R_ab).
- 利用对称性调整的扰动理论来合理化发现.
- 将模拟结果与没有扩展的长距离三体交换相互作用进行比较.
主要成果:
- 长距离的三体交换相互作用对于准确预测液态水的温度密度 (ρ(T)) 至关重要.
- 这些影响对于大多数其他水性质是可以忽略不计的.
- 非极化三体效应在较大的距离下衰减为1/R_ab^n,而不是指数式,由于异极性而显著影响水的结构和密度.
结论:
- 高精度的水模型必须包含远程三体交换相互作用,特别是密度预测.
- 这些相互作用的异质性是它们对液态水温度依赖密度的强烈影响的关键.
- 这项研究有助于解决水密度的理论-实验差异.
相关概念视频
Intermolecular Forces
75.7K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
75.7K
Intermolecular Forces
19.4K
19.4K
Van der Waals Interactions
72.8K
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
72.8K
Intermolecular Forces and Physical Properties
29.3K
29.3K
Nonideal Two-Component Liquid Solutions
34
Nonideal liquid solutions, also known as real solutions, do not strictly follow Raoult's law. Raoult's law is a rule of thumb in physical chemistry. However, not all mixtures adhere to this law due to varying molecular interactions. For example, in an acetone/chloroform solution, the individual vapor pressures of the components are lower than expected, resulting in a total vapor pressure below that predicted by Raoult's law, causing a negative deviation.On the other hand, in an ethanol/water...
34
Two Components: Liquid–Liquid Systems
72
A pressure-composition phase diagram explicitly describes the behavior of an ideal solution of two volatile liquids under varying pressures and compositions. A pressure-composition diagram has two main curves. The bubble point curve represents the plot of pressure versus liquid mole fraction. It indicates the pressure at which the first bubble of vapor forms from the liquid phase as the system pressure decreases.The dew point curve is the pressure versus vapor mole fraction. It indicates the...
72


