论文标题
对分子间相互作用能的电荷转移贡献的非扰动成对加addive分析
A Non-Perturbative Pairwise-Additive Analysis of Charge Transfer Contributions to Intermolecular Interaction Energies
论文作者
论文摘要
基于绝对局部的分子轨道(ALMO)的能量分解分析(EDA)将分子之间的相互作用能分解为物理上可解释的成分,例如几何变形,冷冻相互作用,极化和电荷转移(CT,有时也称为电荷无限化)相互作用。在这项工作中,使用密度函数理论引入了将CT相互作用能量分解为成对添加剂项的数值精确方案。与扰动成对电荷分解分析不同,新方法不会针对强烈相互作用的系统分解,也不会显示出分解能量成分中显着的交换相关功能依赖性。降低能量和与CT相关的电荷流都可以分解。捕获主要的供体和受体CT轨道的互补占用的虚拟轨道对(COVP)是为新分解而获得的。它应用于具有不同类型相互作用的系统,包括DNA碱基对,硼烷 - ammonia加合物和过渡金属己酮。尽管与这些系统中CT性质的大多数现有理解一致,但结果还揭示了一些对供体 - 受体相互作用趋势起源的新见解。
Energy decomposition analysis (EDA) based on absolutely localized molecular orbitals (ALMOs) decomposes the interaction energy between molecules into physically interpretable components like geometry distortion, frozen interactions, polarization, and charge transfer (CT, also sometimes called charge delocalization) interactions. In this work, a numerically exact scheme to decompose the CT interaction energy into pairwise additive terms is introduced for the ALMO-EDA using density functional theory. Unlike perturbative pairwise charge-decomposition analysis, the new approach does not break down for strongly interacting systems, or show significant exchange-correlation functional dependence in the decomposed energy components. Both the energy lowering and the charge flow associated with CT can be decomposed. Complementary occupied-virtual orbital pairs (COVPs) that capture the dominant donor and acceptor CT orbitals are obtained for the new decomposition. It is applied to systems with different types of interactions including DNA base-pairs, borane-ammonia adducts, and transition metal hexacarbonyls. While consistent with most existing understanding of the nature of CT in these systems, the results also reveal some new insights into the origin of trends in donor-acceptor interactions.