Geometric and electronic structure of AlO4 and

Electronic structure calculations using the BPW91, B3LYP, MP2, and CCSD(T) approximations, in conjunction with the 6-311+G(2df) basis set, have been performed to obtain optimized geometries and energies of the low-lying states of AlO4 and AlO 4 - . At the CCSD(T) level, the 2A2 (C2v) dioxo-superoxide is at least 0.5 eV lower in energy than both the 2A2 (D2d) and 2B1 (C2v) isomers earlier predicted for the ground state. The calculations find a 1A1 (D2d) ground state for AlO 4 - . The anion is stable toward electron detachment with vertical electron detachment energy of 4.65 eV and adiabatic electron detachment energy of 4.37 eV.