New ab initio potential energy surface and the vibration-rotation-tunneling levels of (H2O)2 and (D2O)2
New ab initio potential energy surface and the vibration-rotation-tunneling levels of (H2O)2 and (D2O)2
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DOI：
10.1063/1.2822115
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发表时间：
2008-01-21
影响因子：
4.4
通讯作者：
van der Avoird, Ad
中科院分区：
文献类型：
--
作者：
Huang, X.;Braams, Bastiaan J.;van der Avoird, Ad
我们报告了一种新的水二聚体的全维势能表面（PES），该表面基于通过耦合簇单和双获得的大约 30 000 个配置的拟合能量，以及使用增强的、相关一致的、偏振三 zeta 基组的三重激发方法的微扰处理。还报告了基于这些配置的 Moller-Plesset 微扰理论结果的全局偶极矩表面。 PES 用于使用刚性单体近似对 (H2O)(2) 和 (D2O)(2) 的分子间振动频率、隧道分裂和旋转常数进行严格的量子计算。与实验的一致性非常好，并且处于迄今为止报告的最高水平。通过将该模型中的隧道障碍与完全松弛计算中的隧道障碍进行比较来检验该近似的有效性。 (c) 2008 年美国物理研究所。
We report a new full-dimensional potential energy surface (PES) for the water dimer, based on fitting energies at roughly 30 000 configurations obtained with the coupled-cluster single and double, and perturbative treatment of triple excitations method using an augmented, correlation consistent, polarized triple zeta basis set. A global dipole moment surface based on Moller-Plesset perturbation theory results at these configurations is also reported. The PES is used in rigorous quantum calculations of intermolecular vibrational frequencies, tunneling splittings, and rotational constants for (H2O)(2) and (D2O)(2), using the rigid monomer approximation. Agreement with experiment is excellent and is at the highest level reported to date. The validity of this approximation is examined by comparing tunneling barriers within that model with those from fully relaxed calculations. (c) 2008 American Institute of Physics.