Sharkas Kamal, 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.
J Phys Chem A. 2017 Dec 7;121(48):9392-9400. doi: 10.1021/acs.jpca.7b09779. Epub 2017 Nov 28.
We investigate the performance of multiconfiguration pair-density functional theory (MC-PDFT) and complete active space second-order perturbation theory for computing the bond dissociation energies of the diatomic molecules FeC, NiC, FeS, NiS, FeSe, and NiSe, for which accurate experimental data have become recently available [Matthew, D. J.; Tieu, E.; Morse, M. D. J. Chem. Phys. 2017, 146, 144310-144320]. We use three correlated participating orbital (CPO) schemes (nominal, moderate, and extended) to define the active spaces, and we consider both the complete active space (CAS) and the separated-pair (SP) schemes to specify the configurations included for a given active space. We found that the moderate SP-PDFT scheme with the tPBE on-top density functional has the smallest mean unsigned error (MUE) of the methods considered. This level of theory provides a balanced treatment of the static and dynamic correlation energies for the studied systems. This is encouraging because the method is low in cost even for much more complicated systems.
我们研究了多组态对密度泛函理论（MC-PDFT）和完全活性空间二阶微扰理论在计算双原子分子FeC、NiC、FeS、NiS、FeSe和NiSe的键解离能方面的性能，最近已有这些分子精确的实验数据[Matthew, D. J.; Tieu, E.; Morse, M. D. J. Chem. Phys. 2017, 146, 144310 - 144320]。我们使用三种相关参与轨道（CPO）方案（标称、适度和扩展）来定义活性空间，并考虑完全活性空间（CAS）和分离对（SP）方案来指定给定活性空间所包含的构型。我们发现，采用tPBE表面密度泛函的适度SP-PDFT方案在所考虑的方法中具有最小的平均绝对误差（MUE）。该理论水平为所研究的体系提供了对静态和动态相关能的平衡处理。这是令人鼓舞的，因为即使对于复杂得多的体系，该方法成本也较低。
