Pandharkar Riddhish, Hermes Matthew R, Truhlar Donald G, Gagliardi Laura
Department of Chemistry, Pritzker School of Molecular Engineering, James Franck Institute, and Chicago Center for Theoretical Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.
Department of Chemistry, Chemical Theory Center, and The Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States.
J Phys Chem Lett. 2020 Dec 3;11(23):10158-10163. doi: 10.1021/acs.jpclett.0c02956. Epub 2020 Nov 16.
We propose a hybrid multiconfiguration pair-density functional theory (HMC-PDFT) that is a weighted average of complete-active-space self-consistent-field (CASSCF) and multiconfiguration pair-density functional theory (MC-PDFT) energies with a semiempirical parameter to control the fraction of CASSCF energy. We also explore a more general two-parameter hybrid method with a scaled correlation energy that allows us to compare to the recently proposed λ-MC-PDFT method. We scan the parameter space for the scaled-correlation method using test sets consisting of electronic excitation energies and diatomic bond energies, and we find no significant improvement by introducing the scaling parameter. We find that unscaled HMC-PDFT offers significantly improved accuracy over both CASSCF and the original MC-PDFT for a wide range of systems, and we present as an example of this approach "tPBE0", the "translated" MC-PDFT generalization of the popular PBE0 hybrid Kohn-Sham density functional.
我们提出了一种混合多组态对密度泛函理论（HMC-PDFT），它是完全活性空间自洽场（CASSCF）和多组态对密度泛函理论（MC-PDFT）能量的加权平均值，带有一个半经验参数来控制CASSCF能量的占比。我们还探索了一种更通用的双参数混合方法，该方法具有缩放后的相关能，这使我们能够与最近提出的λ-MC-PDFT方法进行比较。我们使用由电子激发能和双原子键能组成的测试集扫描缩放相关方法的参数空间，发现引入缩放参数并没有显著的改进。我们发现，对于广泛的体系，未缩放的HMC-PDFT在精度上比CASSCF和原始的MC-PDFT都有显著提高，并且我们给出了这种方法的一个例子“tPBE0”，它是流行的PBE0混合Kohn-Sham密度泛函的“平移”MC-PDFT泛函。
