Kim Min-Cheol, Sim Eunji, Burke Kieron
Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749, South Korea.
Department of Chemistry, University of California, Irvine, California 92697, USA.
J Chem Phys. 2014 May 14;140(18):18A528. doi: 10.1063/1.4869189.
Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO·Cl(-) and HO·H2O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.
标准密度泛函近似对于奇电子自由基配合物常常给出有问题的结果，误差通常归因于自相互作用。在密度校正密度泛函理论（DC-DFT）中，通过使用比自洽密度更精确的密度，某些类别的密度泛函理论计算得到了显著改进。我们讨论了如何识别这类情况，以及DC-DFT如何更广泛地应用。为了说明这一点，我们使用各种常见的近似泛函，在有和没有这种密度校正的情况下，计算了HO·Cl(-)和HO·H2O配合物的势能面。当自洽计算时，常用的近似给出形状错误的表面和/或不正确的最小值，而在密度校正时给出几乎相同的形状和最小值。即使存在隐式溶剂，这种改进仍然保留。
