Bao Junwei Lucas, Wang Ying, He Xiao, Gagliardi Laura, Truhlar Donald G
Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States.
School of Chemistry and Molecular Engineering, State Key Laboratory of Precision Spectroscopy, East China Normal University , Shanghai 200062, China.
J Phys Chem Lett. 2017 Nov 16;8(22):5616-5620. doi: 10.1021/acs.jpclett.7b02705. Epub 2017 Nov 6.
Delocalization error has been singled out by Yang and co-workers as the dominant error in Kohn-Sham density functional theory (KS-DFT) with conventional approximate functionals. In this Letter, by computing the vertical first ionization energy for well separated He clusters, we show that multiconfiguration pair-density functional theory (MC-PDFT) is free from delocalization error. To put MC-PDFT in perspective, we also compare it with some Kohn-Sham density functionals, including both traditional and modern functionals. Whereas large delocalization errors are almost universal in KS-DFT (the only exception being the very recent corrected functionals of Yang and co-workers), delocalization error is removed by MC-PDFT, which bodes well for its future as a step forward from KS-DFT.
离域误差已被杨及其同事指出是传统近似泛函的Kohn-Sham密度泛函理论（KS-DFT）中的主要误差。在本信函中，通过计算分离良好的氦团簇的垂直第一电离能，我们表明多组态对密度泛函理论（MC-PDFT）不存在离域误差。为了全面了解MC-PDFT，我们还将其与一些Kohn-Sham密度泛函进行了比较，包括传统泛函和现代泛函。虽然离域误差在KS-DFT中几乎普遍存在（唯一的例外是杨及其同事最近修正的泛函），但MC-PDFT消除了离域误差，这预示着它作为从KS-DFT向前迈进的一步，未来前景良好。
