School of Physics and Astronomy and the Thomas Young Centre for Theory and Simulation of Materials at Queen Mary University of London , London E1 4NS , U.K.
J Chem Theory Comput. 2020 Jan 14;16(1):224-242. doi: 10.1021/acs.jctc.9b00819. Epub 2019 Dec 10.
The many-body polarization energy is the major source of nonadditivity in strongly polar systems such as water. This nonadditivity is often considerable and must be included, if only in an average manner, to correctly describe the physical properties of the system. Models for the polarization energy are usually parametrized using experimental data, or theoretical estimates of the many-body effects. Here we show how many-body polarization models can be developed for water complexes using data for the monomer and dimer only using ideas recently developed in the field of intermolecular perturbation theory and state-of-the-art approaches for calculating distributed molecular properties based on the iterated stockholder atoms (ISA) algorithm. We show how these models can be calculated, and we validate their accuracy in describing the many-body nonadditive energies of a range of water clusters. We further investigate their sensitivity to the details of the polarization damping models used. We show how our very best polarization models yield many-body energies that agree with those computed with coupled-cluster methods, but at a fraction of the computational cost.
多体极化能是水等强极性体系中非加和性的主要来源。这种非加和性通常是相当大的，如果要正确描述体系的物理性质，就必须以平均的方式包括在内。极化能模型通常使用实验数据或多体效应的理论估计进行参数化。在这里，我们展示了如何仅使用单体和二聚体的数据，使用最近在分子间微扰理论领域发展的思想和基于迭代股东原子（ISA）算法计算分布式分子性质的最先进方法，为水配合物开发多体极化模型。我们展示了如何计算这些模型，并验证了它们在描述一系列水分子簇的多体非加和能量方面的准确性。我们进一步研究了它们对所使用的极化阻尼模型细节的敏感性。我们展示了我们最好的极化模型如何产生与耦合簇方法计算的多体能量一致的结果，但计算成本只是其一小部分。
