Tran Van Tan
Theoretical and Physical Chemistry Division, Dong Thap University, 783-Pham Huu Lau, Cao Lanh City, Dong Thap, Vietnam.
J Phys Chem A. 2021 Jul 8;125(26):5800-5810. doi: 10.1021/acs.jpca.1c04469. Epub 2021 Jun 27.
Density matrix renormalization group-CASPT2 (DMRG-CASPT2), CASPT2, and density functional theory are employed to describe the complicated geometrical and electronic structures of CoSi ( = 1-3) clusters. The active spaces of DMRG-CASPT2 are extended to 23 orbitals. The DMRG-CASPT2 method with such large active spaces is reasonable to provide highly accurate relative energies of the electronic states. The pure BP86, PBE, and TPSS functionals appear to be suitable to compute the relative energies of the electronic states of cobalt-doped silicon clusters. The leading configurations, bond distances, vibrational frequencies, normal modes, and relative energies of the electronic states are reported. The electron detachment energies of the removals of one electron from the anionic and neutral clusters are estimated. All six bands in the photoelectron spectrum of CoSi are interpreted based on the computed electron detachment energies and Franck-Condon factor simulations.
采用密度矩阵重整化群 - 完全活性空间二阶微扰理论（DMRG - CASPT2）、完全活性空间二阶微扰理论（CASPT2）和密度泛函理论来描述CoSi（n = 1 - 3）团簇复杂的几何结构和电子结构。DMRG - CASPT2的活性空间扩展到23个轨道。具有如此大活性空间的DMRG - CASPT2方法对于提供电子态的高精度相对能量是合理的。纯BP86、PBE和TPSS泛函似乎适合计算钴掺杂硅团簇电子态的相对能量。报告了电子态的主要构型、键长、振动频率、简正模式和相对能量。估计了从阴离子和中性团簇中移除一个电子的电子脱离能。基于计算得到的电子脱离能和弗兰克 - 康登因子模拟，对CoSi光电子能谱中的所有六个能带进行了解释。
