高级量子化学从头计算法研究N_2和H_2O分子间相互作用

High Level Ab Initio MO Study on the H_2O Interacting with N_2

在 MP2 / 6-3 1 1 + + G(3 d,3 p)电子相关校正水平上 ,对 N2 和 H2 O分子间可能存在的氢键复合物进行全自由度能量梯度优化 ,发现了一个接近于直线的弱氢键总能量极小结构 (1 ) ,进一步在高级电子相关校正的 MP4SDTQ和 CCSD(T)水平 ,用 6-3 1 1 + + G(3 d,3 p)基组加上 (3 s3 p2 d1 f)键函数 ,用 MP4和 CCSD(T)计算的结构 1的结合能分别为 -5 .0 61 k J/ mol和 -4 .71 5 k J/ mol.

Ab initio molecular orbital calculations including MP2 correlation energy have been employed to optimize the geometries of the H_2O and N_2 complexes by using 6-311++G(3d,3p) basis set. It was found that a stable minimized structure has a nearly linear hydrogen bonded geometry, the binding energy of which was calculated by use of MP2, MP4SDTQ and CCSD(T) methods by using 6-311++G(3d,3p) basis set adding mid-bond function (3s3p2d1f). The calculated binding energy is -5.061 kJ/mol at the MP4SDTQ and -4.715 kJ/mol at the CCSD(T) level.