Anchoring the potential energy surface of the cyclic water trimer
Anchoring the potential energy surface of the cyclic water trimer
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DOI：
10.1063/1.1799931
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发表时间：
2004-12-08
影响因子：
4.4
通讯作者：
Tschumper, GS
中科院分区：
文献类型：
--
作者：
Anderson, JA;Crager, K;Tschumper, GS
采用aug-cc-pVQZ基组，在MP2水平上对水三聚体势能面上的六个循环驻点进行了优化.与以前的工作一致，谐波振动频率表明，两个结构是最小值，三个是过渡态连接表面上的最小值，而其余的驻点是一个高阶鞍点。通过系统地改变基组和理论方法来估计这六种结构中每一种的电子能量的1-和n-粒子极限。前一个极限用cc-pVXZ和aug-cc-pVXZ基组族（X=2-7）来接近，而MP2、CCSD（T）和BD（TQ）计算有助于检验后者。还在MP2水平上用cc-pCVXZ系列基组（X=2-5）评估了核心相关效应。这些数据已经结合起来，提供高度准确的相对能量和离解能为这些固定点。(C)2004年，美国物理学会。
Six cyclic stationary points on the water trimer potential energy surface have been fully optimized at the MP2 level with the aug-cc-pVQZ basis set. In agreement with previous work, harmonic vibrational frequencies indicate that two structures are minima, three are transition states connecting minima on the surface while the remaining stationary point is a higher-order saddle point. The 1- and n-particle limits of the electronic energies of each of these six structures were estimated by systematically varying both the basis sets and theoretical methods. The former limit was approached with the cc-pVXZ and aug-cc-pVXZ families of basis sets (X=2-7) while MP2, CCSD(T), and BD(TQ) calculations helped examine the latter. Core correlation effects have also been assessed at the MP2 level with the cc-pCVXZ series of basis sets (X=2-5). These data have been combined to provide highly accurate relative energies and dissociation energies for these stationary points. (C) 2004 American Institute of Physics.