水分子六聚体的分子间相互作用。

Intermolecular interaction in water hexamer.

机构信息

Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.

出版信息

J Phys Chem A. 2010 Nov 4;114(43):11719-24. doi: 10.1021/jp104822e.

PMID:20932059

Abstract

The origin of the intermolecular interaction, especially the many-body interaction, in eight low-lying water hexamer structures (prism, cage, book-1, book-2, cyclic-chair, bag, cyclic-boat-1, and cyclic-boat-2) is unraveled using the localized molecular orbital energy decomposition analysis (LMO-EDA) method at the second-order Møller-Plesset perturbation (MP2) level of theory with a large basis set. It is found that the relative stabilities of these hexamer structures are determined by delicate balances between different types of interaction. According to LMO-EDA, electrostatic and exchange interactions are strictly pairwise additive. Dispersion interaction in these water hexamer structures is almost pairwise additive, with many-body effects varying from -0.13 to +0.05 kcal/mol. Repulsion interaction is roughly pairwise additive, with many-body effects varying from -0.84 to -0.62 kcal/mol. Polarization interaction is not pairwise additive, with many-body effects varying from -13.10 to -8.85 kcal/mol.

摘要

使用本地化分子轨道能量分解分析（LMO-EDA）方法，在二阶 Møller-Plesset 微扰（MP2）理论水平和大基组上，揭示了八种低能水六聚体结构（棱柱、笼、书-1、书-2、环状椅、袋、环状船-1 和环状船-2）中分子间相互作用，特别是多体相互作用的起源。结果发现，这些六聚体结构的相对稳定性是由不同类型相互作用之间的微妙平衡决定的。根据 LMO-EDA，静电和交换相互作用是严格的两两加和的。这些水中六聚体结构中的色散相互作用几乎是两两加和的，多体效应在-0.13 到+0.05 kcal/mol 之间变化。排斥相互作用大致是两两加和的，多体效应在-0.84 到-0.62 kcal/mol 之间变化。极化相互作用不是两两加和的，多体效应在-13.10 到-8.85 kcal/mol 之间变化。