How good are polarizable and flexible models for water: Insights from a many-body perspective
How good are polarizable and flexible models for water: Insights from a many-body perspective
复制标题
DOI：
10.1063/5.0017590
复制
发表时间：
2020-08-14
影响因子：
4.4
通讯作者：
Paesani, Francesco
中科院分区：
文献类型：
--
作者：
Lambros, Eleftherios;Paesani, Francesco
我们提出了一个系统的分析国家的最先进的可极化和灵活的水模型从多体的角度来看，特别关注他们的能力，以表示从气体到液相的水的伯恩奥本海默势能面。使用耦合集群数据在完成的基组限制作为参考，我们检查的准确性的极化模型在再现个人的多体贡献的相互作用能和谐波频率的水集群和比较其性能与MB-波尔，一个明确的多体模型，已被证明可以正确地预测整个相图的水的属性。基于这些比较，我们使用MB-pol作为参考来分析极化模型在环境条件下再现液态水能量景观的能力。我们发现，虽然正确地再现能量最小的能量结构，在这项研究中检查的极化模型遭受的扭曲配置的多体效应的代表性不足。为了研究1-体电荷分布的几何相关表示在再现相互作用和多体能量的耦合簇数据中所起的作用，我们引入了一个简化版本的MB-波尔，采用固定的原子电荷，并证明新模型保留了相同的精度作为原始MB-波尔模型。基于本研究中提出的分析，我们认为，极化和显式多体模型的未来发展应继续并行，并将受益于协同努力，旨在整合两个理论/计算框架的最佳方面。
We present a systematic analysis of state-of-the-art polarizable and flexible water models from a many-body perspective, with a specific focus on their ability to represent the Born-Oppenheimer potential energy surface of water from the gas to the liquid phase. Using coupled cluster data in the completed basis set limit as a reference, we examine the accuracy of the polarizable models in reproducing individual many-body contributions to interaction energies and harmonic frequencies of water clusters and compare their performance with that of MB-pol, an explicit many-body model that has been shown to correctly predict the properties of water across the entire phase diagram. Based on these comparisons, we use MB-pol as a reference to analyze the ability of the polarizable models to reproduce the energy landscape of liquid water under ambient conditions. We find that, while correctly reproducing the energetics of minimum-energy structures, the polarizable models examined in this study suffer from inadequate representations of many-body effects for distorted configurations. To investigate the role played by geometry-dependent representations of 1-body charge distributions in reproducing coupled cluster data for both interaction and many-body energies, we introduce a simplified version of MB-pol that adopts fixed atomic charges and demonstrate that the new model retains the same accuracy as the original MB-pol model. Based on the analyses presented in this study, we believe that future developments of both polarizable and explicit many-body models should continue in parallel and would benefit from synergistic efforts aimed at integrating the best aspects of the two theoretical/computational frameworks.