Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States.
Materials Science and Engineering, University of California San Diego, La Jolla, California 92093, United States.
J Phys Chem B. 2020 Dec 10;124(49):11207-11221. doi: 10.1021/acs.jpcb.0c08728. Epub 2020 Nov 24.
Many-body potential energy functions (PEFs) based on the TTM-nrg and MB-nrg theoretical/computational frameworks are developed from coupled cluster reference data for neat methane and mixed methane/water systems. It is shown that the MB-nrg PEFs achieve subchemical accuracy in the representation of individual many-body effects in small clusters and enables predictive simulations from the gas to the liquid phase. Analysis of structural properties calculated from molecular dynamics simulations of liquid methane and methane/water mixtures using both TTM-nrg and MB-nrg PEFs indicates that, while accounting for polarization effects, is important for a correct description of many-body interactions in the liquid phase, an accurate representation of short-range interactions, as provided by the MB-nrg PEFs, is necessary for a quantitative description of the local solvation structure in liquid mixtures.
基于 TTM-nrg 和 MB-nrg 理论/计算框架的多体势能函数 (PEFs) 是从纯甲烷和混合甲烷/水体系的耦合簇参考数据中开发出来的。结果表明，MB-nrg PEFs 在小团簇中对单个多体效应的表示达到了亚化学精度，并能够从气相到液相进行预测性模拟。使用 TTM-nrg 和 MB-nrg PEFs 对液态甲烷和甲烷/水混合物的分子动力学模拟计算的结构性质进行分析表明，虽然考虑极化效应对于正确描述液相中的多体相互作用很重要，但准确表示短程相互作用，如 MB-nrg PEFs 所提供的，对于定量描述液体混合物中的局部溶剂化结构是必要的。
