title: Electronic Structure of Neutral and Anionic Scandium Disilicon ScSi2-/0Clusters and the Related Anion Photoelectron Spectrum.
abstract: Several quantum chemical methods including DFT (B3LYP, BP86 functional), coupled-cluster theory (RCCSD(T)), and complete active space multiconfigurational methods (CASSCF/CASPT2) were used to study the geometric and electronic structures of the scandium disilicon cluster in both neutral and anionic states, ScSi2-/0. On the basis of the computed ground and lower-lying electronic states, and ionization energies of the anion, all the experimental bands in the anion photoelectron spectrum of ScSi2-can now fully be elucidated. The3B2and2B2states are determined to be the ground states of the anionic and the neutral triatomic species, respectively. The transition3B2→2B2is thus assigned to be responsible for the X band in the photoelectron spectrum. The2A1neutral state is the final state corresponding to the A band. Although the first two bands arise from ionizations of scandium's 4s and 3d orbitals, all three remaining bands with higher ionization energies are the results of one-electron removals from the Si2moiety orbitals of the anionic ground state3B2. Two electronic states of the same representations 14B2and 24B2are ascribed to be the carriers of the B and C bands, whereas the excited state4A2is attributed to the last band D of the experimental photoelectron spectrum of ScSi2-. From all accessible vibrations of the ground and excited states computed at the B3LYP level, a simulation of band progressions in the photoelectron spectrum was also carried out and used to provide more insights into the experimental bands.
authors.affiliation: Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001Leuven, Belgium.
authors.forename: Le Nhan
authors.initials: LN
authors.lastname: Pham
authors.affiliation: Computational Chemistry Research Group, Ton Duc Thang University , Ho Chi Minh City, Vietnam.|Faculty of Applied Sciences, Ton Duc Thang University , Ho Chi Minh City, Vietnam.|Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001Leuven, Belgium.
authors.forename: Minh Tho
authors.initials: MT
authors.lastname: Nguyen