An ab initio study of the torsional-puckering pseudorotation in the cyclic water pentamer
An ab initio study of the torsional-puckering pseudorotation in the cyclic water pentamer
复制标题
环状水五聚体扭转褶皱假旋转的从头算研究
DOI：
10.1063/1.478695
复制
发表时间：
1999
影响因子：
4.4
通讯作者：
S. Leutwyler
中科院分区：
文献类型：
--
作者：
S. Graf;Wolfgang Mohr;S. Leutwyler
在二阶Moller-Plesset摄动理论的水平上，利用包含扩散函数的双ζ和三ζ相关一致基集，从理论上研究了环同形水五聚体的分子间势能面和扭转-皱缩运动。广泛的搜索得到了三个循环同形平稳点：(i)皱化的全球最小结构GS， （ii）一个高62 cm−1的扭转-皱化鞍点，记为TS1， （iii）一个平面C5h对称结构（Hessian指数7），能量高800 cm−1。计算了各平稳点的谐波振动频率和正态模态。基于GS和TS1结构的能量和二阶导数，构造了具有十个置换等效极小值的大振幅TP运动的循环最小能量路径。基态和所有激发态通过TP伪旋转离域，得到振动平均C5h对称性。第一个伪旋转…
The intermolecular potential energy surface and the torsional-puckering (TP) motion of the cyclic homodromic water pentamer were theoretically investigated at the level of second-order Moller–Plesset perturbation theory using double- and triple-zeta correlation-consistent basis sets including diffuse functions. Extensive searches yielded three cyclic homodromic stationary points: (i) the puckered global minimum structure GS, (ii) a torsional-puckering saddle point, 62 cm−1 higher, denoted TS1, and (iii) a planar C5h symmetric structure (Hessian index 7), 800 cm−1 higher in energy. Harmonic vibrational frequencies and normal modes were calculated for all stationary points. Based on the energies and second derivatives of the GS and TS1 structures a cyclic minimum energy path for the large-amplitude TP motion with ten permutationally equivalent minima was constructed. The ground and all excited states are delocalized by TP pseudorotation, giving vibrationally averaged C5h symmetry. The first pseudorotational...