Department of Chemistry , Iowa State University , Ames , Iowa 50011 , United States.
Ames Laboratory , Ames , Iowa 50011 , United States.
J Phys Chem A. 2019 Oct 3;123(39):8406-8416. doi: 10.1021/acs.jpca.9b05977. Epub 2019 Sep 24.
Many-body dispersion has gained considerable attention over the past decade, particularly for condensed phase systems. However, quantitatively accurate studies of many-body dispersion have only recently become feasible due to challenges in reliability and accuracy. Currently available methodologies for calculating many-body dispersion have been challenged, with recent evidence suggesting, for example, that dispersion-corrected density functional theory (DFT) schemes cannot consistently predict many-body dispersion accurately. This study evaluates many-body dispersion energies using a composite approach that employs singles and doubles coupled cluster theory with perturbative/noniterative triples, CCSD(T), combined with an extrapolation to the complete basis set (CBS) limit. The combined CCSD(T)/CBS approach is applied to Ar and (HO), = 3-10, clusters, and a new data set called S22(3), which includes trimers generated based on the S22 data set. In these systems, the many-body dispersion provides a very small contribution to the total interaction energy of all of the systems studied, generally 3% or less of the total interaction energy. Two-body dispersion is the dominant dispersion contribution and many-body dispersion contributes no more than 5.7% of the total dispersion energy, generally staying below 2%.
多体色散在过去十年中引起了相当大的关注，特别是对于凝聚相系统。然而，由于可靠性和准确性方面的挑战，多体色散的定量准确研究直到最近才成为可能。目前用于计算多体色散的方法学受到了挑战，例如，最近的证据表明，经色散校正的密度泛函理论（DFT）方案不能始终如一地准确预测多体色散。本研究使用一种组合方法评估多体色散能，该方法采用单激发和双激发耦合簇理论与微扰/非迭代三激发项 CCSD(T) 相结合，并结合完全基组（CBS）极限外推。组合 CCSD(T)/CBS 方法应用于 Ar 和 (HO)，n = 3-10 团簇，以及一个新的数据集 S22(3)，其中包括基于 S22 数据集生成的三聚体。在这些系统中，多体色散对所有研究系统的总相互作用能的贡献非常小，通常占总相互作用能的 3%或以下。二体色散是主要的色散贡献，多体色散对总色散能的贡献不超过 5.7%，通常低于 2%。
