Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
J Chem Phys. 2012 Dec 14;137(22):224314. doi: 10.1063/1.4770263.
We report a new three-dimensional ab initio intermolecular potential energy surface for the Kr-H(2)O complex with the H(2)O monomer fixed at its experimental averaged structure. Using the supermolecular approach, the intermolecular potential energies were evaluated at the coupled-cluster singles and doubles level with noniterative inclusion of connected triples with the full counterpoise correction for the basis set superposition error and a large basis set including bond functions. The global minimum corresponding to a planar H-bond configuration was located at the intermolecular distance of 3.82 Å with a well depth of 169.98 cm(-1). In addition, two first-order and one second-order saddle points were also identified. The combined radial discrete variable representation∕angular finite basis representation method and the Lanczos algorithm were employed to calculate the rovibrational energy levels for 16 isotopic species of the Kr-H(2)O complexes. The rotational transition frequencies, structure parameters, and nuclear quadrupole coupling constants were also determined for the ground and first intermolecular vibrational excited states and are all in good agreement with the available experimental values.
我们报道了一种新的 Kr-H(2)O 复合物的三维从头算分子间势能面，其中 H(2)O 单体固定在其实验平均结构上。使用超分子方法，在耦合簇单双激发水平上评估了分子间势能，其中包括非迭代包含连接三态，以及全对易校正的基组超位误差和包括键函数的大基组。对应于平面氢键构型的全局最小值位于 3.82Å 的分子间距离处，具有 169.98cm(-1)的深阱。此外，还确定了两个一阶和一个二阶鞍点。采用径向离散变量表示/角有限基表示方法和 Lanczos 算法，计算了 Kr-H(2)O 复合物的 16 种同位素的 rovibrational 能级。还确定了基态和第一分子间振动激发态的转动跃迁频率、结构参数和核四极耦合常数，它们与现有的实验值吻合良好。
