Zhou Nengjie, Lu Zhenyu, Wu Qin, Zhang Yingkai
Department of Chemistry, New York University, New York, New York 10003, USA.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
J Chem Phys. 2014 Jun 7;140(21):214117. doi: 10.1063/1.4881255.
We examine interatomic interactions for rare gas dimers using the density-based energy decomposition analysis (DEDA) in conjunction with computational results from CCSD(T) at the complete basis set (CBS) limit. The unique DEDA capability of separating frozen density interactions from density relaxation contributions is employed to yield clean interaction components, and the results are found to be consistent with the typical physical picture that density relaxations play a very minimal role in rare gas interactions. Equipped with each interaction component as reference, we develop a new three-term molecular mechanical force field to describe rare gas dimers: a smeared charge multipole model for electrostatics with charge penetration effects, a B3LYP-D3 dispersion term for asymptotically correct long-range attractions that is screened at short-range, and a Born-Mayer exponential function for the repulsion. The resulted force field not only reproduces rare gas interaction energies calculated at the CCSD(T)/CBS level, but also yields each interaction component (electrostatic or van der Waals) which agrees very well with its corresponding reference value.
我们结合在完备基组（CBS）极限下CCSD（T）的计算结果，使用基于密度的能量分解分析（DEDA）来研究稀有气体二聚体的原子间相互作用。利用DEDA将冻结密度相互作用与密度弛豫贡献分离的独特能力，得到了清晰的相互作用组分，结果发现与密度弛豫在稀有气体相互作用中作用极小的典型物理图像一致。以每个相互作用组分为参考，我们开发了一种新的三项分子力学力场来描述稀有气体二聚体：具有电荷穿透效应的静电涂抹电荷多极模型、用于短程屏蔽的渐近正确长程吸引的B3LYP-D3色散项以及用于排斥的玻恩-迈耶指数函数。所得力场不仅重现了在CCSD（T）/CBS水平计算的稀有气体相互作用能，还给出了与相应参考值非常吻合的每个相互作用组分（静电或范德华）。
