Generalized Charge Decomposition Analysis (GCDA) Method

电荷分解分析(CDA)是一种重要的深入研究电荷转移问题的方法。本文对CDA进行了介绍，阐述了计算中需要注意的问题，并提出了一种新的CDA形式，称为广义化的电荷分解分析(GCDA)。在HF、DFT级别GCDA与CDA等价，但GCDA能更好地用于后HF计算，而且还明确考虑了开壳层时的计算形式。通过以OC-BH3和顺式二氯二胺合铂体系作为测试实例，我们发现各种理论级别下GCDA的结果都较为合理且定性相符，但在定量上有所区别，特别是d项存在大体趋势：低HF成份的泛函 > 高HF成份的泛函 > HF ≥ MP2 > CCSD。文中还对GCDA计算时基组的选择进行了讨论。 Charge decomposition analysis (CDA) is an important method to study charge transfer problems in depths. In this paper, we introduced CDA method, elucidated the issues that needed attention in the calculation, and presented a new form of CDA, which was called GCDA. At HF and DFT levels, GCDA is equivalent to CDA, while GCDA is more applicable at post-HF level, and meantime its open-shell form is explicitly considered. By taking OC-BH3 and cis-dichlorodiamine as test cases, we find the GCDA results at various theoretical levels are reasonable and qualitatively consistent, but differ quantitatively; in particular, a rough trend exists in the d term: Functional with low HF composition > Functional with high HF composition > HF ≥ MP2 > CCSD. The paper also discussed the choice of basis-set in GCDA calculation.