Huang X, Braams Bastiaan J, Bowman Joel M, Kelly Ross E A, Tennyson Jonathan, Groenenboom Gerrit C, van der Avoird Ad
Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta Georgia 30322, USA.
J Chem Phys. 2008 Jan 21;128(3):034312. doi: 10.1063/1.2822115.
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.
我们报告了一种新的水二聚体全维势能面（PES），它基于使用增强的、相关一致的、极化三重ζ基组，通过耦合簇单双激发以及三重激发微扰处理方法，在大约30000种构型下获得的拟合能量。还报告了基于这些构型下的莫勒-普莱斯特定理微扰理论结果的全局偶极矩面。该势能面用于对（H₂O）₂和（D₂O）₂的分子间振动频率、隧穿分裂和转动常数进行严格的量子计算，采用刚性单体近似。与实验结果的吻合度极佳，达到了迄今为止报道的最高水平。通过比较该模型中的隧穿势垒与完全松弛计算得到的隧穿势垒，检验了这种近似的有效性。
