The low-lying electronic states of ScO₂ and ScO₂⁻: a computational study

The low-lying electronic states of ScO2 and ScO2– were studied using the SAC-CI method. The lowest six doublet states (X2B2, 12A1/22A′, 22A1, 12A2, 12B1/12A″, and 22B2) of ScO2 and the valence-bound singlet/triplet states (X1A1, 21A1/13A1, 11A2/13A2, 11B1/13B1, 11B2/13B2, and 21B2/23B2) of ScO2– were optimised, and the relative energies among these electronic states were obtained. The electron detachment energies from the X1A1 state of ScO2– to the lowest six doublet states of ScO2 and from the 13B2 state of ScO2– to the X2B2 state of ScO2 can be compared with the previous experimental photoelectron spectra of ScO2–. The vertical excitation spectra of ScO2 and ScO2– were computed. The singlet/triplet dipole-bound states (1B2(DB)/3B2(DB)) of ScO2– were found.