Khaliullin Rustam Z, Cobar Erika A, Lochan Rohini C, Bell Alexis T, Head-Gordon Martin
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Phys Chem A. 2007 Sep 13;111(36):8753-65. doi: 10.1021/jp073685z. Epub 2007 Jul 27.
An energy decomposition analysis (EDA) method is proposed to isolate physically relevant components of the total intermolecular interaction energies such as the contribution from interacting frozen monomer densities, the energy lowering due to polarization of the densities, and the further energy lowering due to charge-transfer effects. This method is conceptually similar to existing EDA methods such as Morokuma analysis but includes several important new features. The first is a fully self-consistent treatment of the energy lowering due to polarization, which is evaluated by a self-consistent field calculation in which the molecular orbital coefficients are constrained to be block-diagonal (absolutely localized) in the interacting molecules to prohibit charge transfer. The second new feature is the ability to separate forward and back-donation in the charge-transfer energy term using a perturbative approximation starting from the optimized block-diagonal reference. The newly proposed EDA method is used to understand the fundamental aspects of intermolecular interactions such as the degree of covalency in the hydrogen bonding in water and the contributions of forward and back-donation in synergic bonding in metal complexes. Additionally, it is demonstrated that this method can be used to identify the factors controlling the interaction of the molecular hydrogen with open metal centers in potential hydrogen storage materials and the interaction of methane with rhenium complexes.
提出了一种能量分解分析（EDA）方法，以分离总分子间相互作用能中与物理相关的组分，例如相互作用的冻结单体密度的贡献、密度极化导致的能量降低以及电荷转移效应导致的进一步能量降低。该方法在概念上与现有的EDA方法（如Morokuma分析）相似，但包括几个重要的新特征。第一个特征是对极化导致的能量降低进行完全自洽处理，这通过自洽场计算来评估，其中分子轨道系数在相互作用的分子中被约束为块对角（绝对定域）以禁止电荷转移。第二个新特征是能够使用从优化的块对角参考开始的微扰近似，在电荷转移能量项中分离前向和后向给体作用。新提出的EDA方法用于理解分子间相互作用的基本方面，例如水中氢键的共价程度以及金属配合物中协同键合的前向和后向给体作用的贡献。此外，证明了该方法可用于确定控制潜在储氢材料中分子氢与开放金属中心相互作用以及甲烷与铼配合物相互作用的因素。
