Computational determination of equilibrium geometry and dissociation energy of the water dimer
Computational determination of equilibrium geometry and dissociation energy of the water dimer
复制标题
DOI：
10.1039/a910312k
复制
发表时间：
2000-01-01
影响因子：
3.3
通讯作者：
van Duijneveldt, FB
中科院分区：
文献类型：
--
作者：
Klopper, W;van Duijneveldt-van de Rijdt, JGCM;van Duijneveldt, FB
在技术上尽可能精确地测定了水二聚体的平衡几何构型和离解能。各种量子化学方法和高质量的基组已经被应用--也就是在几乎完全的基水平上--施主和受主分子的分子间分离和形变都在CCSD(T)理论(具有单和双激发的耦合团簇理论加上对连接的三重原子的微扰修正)的水平上进行了优化。结果表明，在CCSD(T)水平上，二聚体中的单体形变占在MP2水平上计算的形变的86%(二阶Moller-Plesset微扰理论)，而在CCSD(T)水平上的核/价电子关联效应占在MP2水平上相同效应的80%。均衡O..。O距离为R-e=291.2+/-0.5 pm，平衡解离能为D-e=21.0+/-0.2kJmol(-1)。在计入零点振动能后，理论预测的离解能为D-0=13.8+/-0.4kJ·mol(-1)，这一结果可供直接实验验证。
The equilibrium geometry and dissociation energy of the water dimer have been determined as accurately as technically possible. Various quantum chemical methods and high-quality basis sets have been applied-that is, at the level of a nearly complete basis-and both the intermolecular separation and the deformation of the donor and acceptor molecules have been optimized at the level of CCSD(T) theory (coupled-cluster theory with singles and doubles excitations plus a perturbation correction for connected triples). It is found at the CCSD(T) level that the monomer deformation in the dimer amounts to 86% of the deformation computed at the MP2 level (second-order Moller-Plesset perturbation theory) and that the core/valence electron correlation effects at the CCSD(T) level amount to 80% of the same effects at the MP2 level. The equilibrium O ... O distance is determined as R-e = 291.2 +/- 0.5 pm and the equilibrium dissociation energy as D-e = 21.0 +/- 0.2 kJ mol(-1), with respect to dissociation into two isolated water molecules at equilibrium. Accounting for zero-point vibrational energy, the theoretical prediction for the dissociation energy becomes D-0 = 13.8 +/- 0.4 kJ mol(-1), a result which is open to direct experimental verification.