The ground and excited low-lying states of VSi20/−/+ clusters from CASSCF/CASPT2 calculations

Abstract The geometric and electronic structures of the ground and excited low-lying states of VSi 2 0/−/+ clusters were investigated by the CASSCF/CASPT2 method. The structural parameters, harmonic vibrational frequencies, relative energies, and atomic charges of the low-lying electronic states were presented and discussed. The ground states of VSi 2 0/−/+ clusters were 4 B 1 , 5 A 1 , and 3 B 1 , respectively. At the CASPT2 level, the electron affinity and ionization energy of the neutral clusters were evaluated to be 1.08 and 7.07 eV, respectively. The vertical detachment energies of the detachments of one electron from several orbitals of the anionic cluster were computed.