多参考态微扰理论大小一致性的数值研究(英文)

• 作 者: 陈飞武
• 机 构: 北京科技大学化学系 北京 100083
• 出 处: 物理化学学报
• 发表日期: 2007年09期
• 关键词: 微扰理论 大小一致性 一致性 组态相互作用 一致性误差 模型空间 超分子 数值研究 数值 模型体系

采用由H_2、He和LiH分别组成的三个超分子系列,从数值的角度研究了多参考态微扰理论和单双重激发的多参考态组态相互作用(MRSDCI)的大小一致性.首先在模型空间中进行一个小的完全组态相互作用计算,然后进行多参考态微扰计算.数值结果显示,对这三个模型体系,我们以前提出的多参考态二级微扰公式是完全大小一致的.和MRSDCI结果比较,我们也对它的计算精度进行了讨论.另外,还对两组多参考态微扰理论的二级和三级计算结果以及MRSDCI的计算结果的大小一致性误差进行了研究和比较.

Using the three supramolecular series consisting of H 2, He and LiH respectively, the consistency of multi-reference state perturbation theory and single-double-excited multi-reference state configuration interaction (MRSDCI) is studied numerically. Firstly, In the model space, a small complete configuration interaction calculation is carried out, and then the multi-reference state perturbation calculation is carried out. Numerical results show that for the three model systems, the previously proposed second-order perturbation formula for multiple reference states is completely consistent in size We also discuss its computational accuracy compared with the MRSDCI results.In addition, the two-level and three-level computational results of the two sets of reference states perturbation theory and the size consistency error of MRSDCI are also calculated Research and comparison.