物理化学学报 >> 2006, Vol. 22 >> Issue (12): 1547-1550.doi: 10.3866/PKU.WHXB20061222

研究简报 上一篇    下一篇

两种哈密顿量划分的单参考态微扰展开式的大小一致性研究

雒飞飞;陈飞武;陈春辉   

  1. (北京科技大学应用科学学院化学系, 北京 100083)
  • 收稿日期:2006-05-15 修回日期:2006-07-06 发布日期:2006-12-06
  • 通讯作者: 陈飞武 E-mail:chenfeiwu@sas.ustb.edu.cn

Size Consistency Study on the Single Reference Perturbation Theory with Two Hamiltonian Partitions

LUO Fei-Fei;CHEN Fei-Wu;CHEN Chun-Hui   

  1. (Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, P. R. China)
  • Received:2006-05-15 Revised:2006-07-06 Published:2006-12-06
  • Contact: CHEN Fei-Wu E-mail:chenfeiwu@sas.ustb.edu.cn

PDF

2679

赞

摘要： 利用一个含N个氢分子的超分子模型, 从解析的角度仔细地分析了相应于两种哈密顿量划分方式的单参考态微扰展开式前四级能量的大小一致性. 对于Epstein-Nesbet划分, 微扰展开式是大小一致的. 而对于另一种划分(Chen, F; Davidson, E. R.; Iwata, S. Int. J. Quantum Chem., 2002, 86: 256, 见公式(24)的讨论), 其展开式大小不一致. 但将它的分母作泰勒展开, 经过重新整理, 将那些大小不一致的项消去后, 得到的新微扰展开式是逐项大小一致的.

关键词: 大小一致性, 单参考态微扰理论, 微扰展开式, 哈密顿量

Abstract: The size-consistency of the single reference perturbation series corresponding to two Hamiltonian partitions has been studied theoretically using an N hydrogen molecular model. One perturbation series corresponding to the so-called Epstein-Nesbet partition was found to be size consistent up to the fourth order, and another perturbation series (Chen, F.; Davidson, E. R.; Iwata, S. Int. J. Quantum Chem., 2002, 86: 256, see the discussions about Eq.(24)) was found to be not size consistent starting from the second order. However, when its denominator was expanded in a Taylor series, a size consistent perturbation expansion was obtained, for the size inconsistent terms turned out to be cancelled out.

Key words: Size consistency, Single reference perturbation theory, Perturbation expansion, Hamiltonian