The selenium oxygen clusters SeOn (n = 1-5) and their anions: Structures and electron affinities

The molecular structures and electron affinities of the SeOn/SeOn- (n = 1-5) species were examined using hybrid Hartree-Fock/density functional theory(DFT). The basis set used in this work was of double-ζ plus polarization quality with additional diffuse s-and p-type functions, denoted DZP++. Seven different density functionals (B3LYP, BLYP, BHLYP, BP86, B3P86, BPW91, and B3PW91) were used in this work. The ground state structures of the SeOn (n = 1-5) was explored in this work. The SeO have a 3Σg− ground state, the SeO2 have an open C2V (ozone-like) structure. For the SeO3, D3h structure is turn to be ground state. The SeO4 has C2V (ozone-like) structure, and The SeO5 has C2 structure. The most reliable adiabatic electron affinities, obtained at the DZP++ BLYP and DZP++ BPW91 level of theory, are be1.38 or 1.40 eV (SeO), 1.87 or 1.89 eV (SeO2), 3.28 or 3.23 eV (SeO3), 4.98 or 4.79 eV (SeO4), 6.15-6.12 eV (SeO5). The BHLYP bond length of the SeO atom, SeO2 molecules predicted by this work are in reasonable agreement with the experimental results. The dissociation energies predicted by the B3P86 method are the most reliable. For the vibrational frequencies of Selenium Oxygen, the B3LYP methods produce good predictions compared with the limited experiments.