Su Neil Qiang, Xu Xin
Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Laboratory for Computational Physical Science, Department of Chemistry, Fudan University , Shanghai 200433, China.
J Chem Theory Comput. 2016 May 10;12(5):2285-97. doi: 10.1021/acs.jctc.6b00197. Epub 2016 Apr 19.
Recently, we have developed an integration approach for the calculations of ionization potentials (IPs) and electron affinities (EAs) of molecular systems at the level of second-order Møller-Plesset (MP2) (Su, N. Q.; Xu, X. J. Chem. Theory Comput. 11, 4677, 2015), where the full MP2 energy gradient with respect to the orbital occupation numbers was derived but only at integer occupations. The theory is completed here to cover the fractional occupation systems, such that Slater's transition state concept can be used to have accurate predictions of IPs and EAs. Antisymmetrized Goldstone diagrams have been employed for interpretations and better understanding of the derived equations, where two additional rules were introduced in the present work specifically for hole or particle lines with fractional occupation numbers.
最近，我们开发了一种用于计算分子体系在二级Møller-Plesset（MP2）水平下的电离势（IPs）和电子亲和能（EAs）的积分方法（苏，N.Q.；徐，X.《化学理论与计算》11，4677，2015），其中推导了相对于轨道占据数的完整MP2能量梯度，但仅适用于整数占据情况。在此将该理论扩展以涵盖分数占据体系，从而可以使用斯莱特过渡态概念对IPs和EAs进行准确预测。已采用反对称戈德斯通图来解释和更好地理解所推导的方程，其中在本工作中专门针对具有分数占据数的空穴或粒子线引入了两条额外规则。
