Theoretical and Physical Chemistry Division , Dong Thap University , 783-Pham Huu Lau , Cao Lanh City , Dong Thap Vietnam.
Quantum Chemistry and Physical Chemistry Division, Chemistry Department , Katholieke Universiteit Leuven , Celestijnenlaan 200F , B-3001 Heverlee-Leuven , Belgium.
J Phys Chem A. 2019 Sep 26;123(38):8265-8273. doi: 10.1021/acs.jpca.9b07583. Epub 2019 Sep 17.
The BP86 DFT, CCSD(T), and CASPT2 methods were employed to study the low-lying states of NbC clusters. The anionic and neutral ground states were determined to be the A and 1A of the cyclic-NbC isomers. All bands in the photoelectron spectra of the NbC cluster were interpreted based on electron detachment processes from the A of the cyclic-NbC isomer. The X, A, B, and C bands in the spectra are, respectively, ascribed to the transitions from A to the 1A, B, 2A, and B states. The wave function of the initial A anionic state exhibits a pronounced multireference character that plays to some extent a role in the A → 1A and the A → 2A ionizations. Only the A → B transition appears as a clear one-electron detachment process. The Franck-Condon factor simulations for the A → 1A and A → B transitions are consistent with the observed vibrational progressions of the X and A bands in the spectra.
采用 BP86DFT、CCSD(T) 和 CASPT2 方法研究了 NbC 团簇的低能态。阴离子和中性基态被确定为环状-NbC 异构体的 A 和 1A。基于从环状-NbC 异构体的 A 中电子脱离过程，解释了 NbC 团簇光电子能谱中的所有谱带。X、A、B 和 C 谱带分别归因于从 A 到 1A、B、2A 和 B 态的跃迁。初始 A 阴离子态的波函数表现出明显的多参考特征，在一定程度上对 A→1A 和 A→2A 电离起到了作用。只有 A→B 跃迁表现为一个明显的单电子脱离过程。A→1A 和 A→B 跃迁的 Franck-Condon 因子模拟与谱中 X 和 A 带的观察到的振动进展一致。
