A modified variation–perturbation approach to zero-point vibrational motion
A modified variation–perturbation approach to zero-point vibrational motion
复制标题
零点振动运动的改进变分扰动方法
DOI：
10.1007/s002149900078
复制
发表时间：
2000
影响因子：
1.7
通讯作者：
D. Sundholm
中科院分区：
文献类型：
--
作者：
P. Åstrand;K. Ruud;D. Sundholm
我们提出了一个详细的调查的微扰方法计算零点振动的分子性质的贡献。结果表明，若将势能与零点振动能之和视为有效势能，则在微扰法中对一阶波函数的主导贡献消失.通过对几个双原子分子的某些磁性的计算，对两种不同的微扰方法进行了数值研究，并将所得结果与精确的数值结果进行了比较。它示出，只有少数条款需要包括在微扰展开，以获得更好的质量比通常获得的潜在的和性质的表面在电子结构计算中的计算的振转贡献的准确性。
We present a detailed investigation of the perturbation approach for calculating zero-point vibrational contributions to molecular properties. It is demonstrated that if the sum of the potential energy and the zero-point vibrational energy is regarded as an effective potential energy, the leading contribution to the first-order wave function vanishes in the perturbation approach. Two different perturbation approaches have been investigated numerically by calculations of some magnetic properties for a few diatomic molecules and the results obtained have been compared to the exact numerical results. It is shown that only a few terms need to be included in a perturbation expansion to obtain an accuracy in the calculated rovibrational contribution better than the quality normally obtained for the potential and property surfaces in electronic structure calculations.