Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
Proc Natl Acad Sci U S A. 2020 Aug 18;117(33):19746-19752. doi: 10.1073/pnas.2005847117. Epub 2020 Aug 3.
The dielectric nature of polar liquids underpins much of their ability to act as useful solvents, but its description is complicated by the long-ranged nature of dipolar interactions. This is particularly pronounced under the periodic boundary conditions commonly used in molecular simulations. In this article, the dielectric properties of a water model whose intermolecular electrostatic interactions are entirely short-ranged are investigated. This is done within the framework of local molecular-field theory (LMFT), which provides a well-controlled mean-field treatment of long-ranged electrostatics. This short-ranged model gives a remarkably good performance on a number of counts, and its apparent shortcomings are readily accounted for. These results not only lend support to LMFT as an approach for understanding solvation behavior, but also are relevant to those developing interaction potentials based on local descriptions of liquid structure.
极性液体的介电性质是其作为有用溶剂的能力的基础,但由于偶极相互作用的长程性质,其描述变得复杂。在分子模拟中常用的周期性边界条件下,这种情况更为明显。在本文中,研究了一种水分子模型的介电性质,该模型的分子间静电相互作用完全是短程的。这是在局部分子场理论(LMFT)的框架内进行的,该理论为长程静电提供了一种很好的控制的平均场处理。这种短程模型在许多方面表现出色,并且其明显的缺点很容易解释。这些结果不仅支持 LMFT 作为理解溶剂化行为的一种方法,而且与那些基于液体结构的局部描述来开发相互作用势能的研究相关。