IBM Research-Zurich, Säumerstr. 4, 8803 Rüschlikon, Switzerland.
J Chem Phys. 2010 Sep 14;133(10):101102. doi: 10.1063/1.3477850.
The Ragot-Cortona or RC model of local correlation energy [J. Chem. Phys. 121, 7671 (2004)] improves the standard local approximation in various respects. This letter aims at illustrating the origin of this improvement. To that aim, simple self-interaction corrected versions of the RC model are implemented, which involve local energy differences only. Several correlation functionals are selected for direct comparison using Hartree-Fock charge densities of atomic ions (H(-) to Ar). One of the self-interaction corrected versions of the RC model shows surprising improvements over the initial RC model. First, it dramatically improves the atomic correlation energies of atomic ions. Second, the impact on the contribution of the correlation energy to ionization potentials or electron affinities is still more convincing. In both cases, the accuracy achieved is close to or better than a selection of gradient-level functionals.
拉各特-科托纳或 RC 局部相关能量模型[J. Chem. Phys. 121, 7671 (2004)]在各个方面改进了标准局部近似。本信旨在阐明这种改进的起源。为此，实现了仅涉及局部能量差的 RC 模型的简单自相互作用修正版本。使用原子离子（H(-)到 Ar）的哈特ree-fock 电荷密度，选择了几种相关泛函进行直接比较。RC 模型的一个自相互作用修正版本显示出对初始 RC 模型的惊人改进。首先，它极大地提高了原子离子的原子相关能量。其次，对电离势或电子亲合势的相关能量贡献的影响更加令人信服。在这两种情况下，所达到的准确性接近或优于梯度水平泛函的选择。
