Zhou Yongxi, Bahmann Hilke, Ernzerhof Matthias
Département de Chimie, Université de Montréal, C.P. 6128, Succursale A, Montréal, Québec H3C 3J7, Canada.
Department of Chemistry, Technische Universität Berlin, Strasse des 17 Juni, Berlin, Germany.
J Chem Phys. 2015 Sep 28;143(12):124103. doi: 10.1063/1.4931160.
Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials.
利用密度泛函理论的绝热连接，构建了Kohn-Sham密度泛函理论的交换相关泛函，这些泛函在电子-电子相互作用强度的极限之间进行插值。第一个极限是无相互作用极限，此时只有交换作用。第二个极限是强关联极限，其特征是电子-电子排斥能的最小值。强关联极限下的交换相关能通过一种称为非局部半径模型的交换相关空穴模型来近似[L. O. Wagner和P. Gori-Giorgi，《物理评论A》90，052512(2014)]。利用无相互作用和强关联极限，提出了各种插值方案，这些方案给出了绝热连接以及交换相关能的新近似。其中一些依赖于经验主义，而另一些则不然。所提出的几种近似方法对于单电子系统能给出精确的交换相关能，而局部和半局部近似在单电子系统中往往表现很差。其他提出的近似方法通过在强关联极限下使用一部分交换相关能来替代强关联极限下半局部近似的交换相关能的相等部分，从而推广了现有的全局杂化方法。针对分子原子化能、总原子能量和电离势对所提出近似方法的性能进行了评估。
