Vydrov Oleg A, Scuseria Gustavo E
Department of Chemistry, Rice University, Houston, TX 77005, USA.
J Chem Phys. 2006 May 21;124(19):191101. doi: 10.1063/1.2204599.
The method of Perdew and Zunger is commonly used to correct the self-interaction error of approximate density functionals. However, it has been shown that this orbital-based self-interaction correction (SIC) tends to overcorrect and often impairs molecular properties. We have recently proposed a method to improve the performance of the SIC by scaling it down in many-electron regions. In this communication, we present a simplification of this scheme. For every occupied orbital, we introduce a scaling factor determined by the ratio of the orbital density to the total spin-density. Thus, the magnitude of the correction is adjusted depending on how much orbital densities overlap with one another. Such a modification of the Perdew-Zunger SIC does not add any appreciable time to the computation, but significantly improves the accuracy for a number of benchmark properties.
佩德韦和宗格的方法通常用于校正近似密度泛函的自相互作用误差。然而，已经表明这种基于轨道的自相互作用校正（SIC）往往会过度校正，并且常常损害分子性质。我们最近提出了一种方法，通过在多电子区域按比例缩小来提高SIC的性能。在本通讯中，我们展示了该方案的一种简化形式。对于每个占据轨道，我们引入一个由轨道密度与总自旋密度之比确定的缩放因子。因此，校正的幅度根据轨道密度相互重叠的程度进行调整。对佩德韦 - 宗格SIC的这种修改不会给计算增加任何可观的时间，但能显著提高许多基准性质的精度。
