The ground state of the cation, three lowest electronic states of the neutral, and two anionic states of Li3O were studied using different ab initio techniques. Stationary points on the potential energy surfaces were determined both at complete active space CAS self-consistent field SCF and at second- order Meoller-Plesset MP2 levels of theory. Excited states were approached using the single-excitation configuration interaction CIS method. Electron detachment energies for the anionic and neutral states were calculated at the quadratic configuration interaction QCI level-with single, double, and approximate triple excitations SDT included. The calculations indicate that Li3O- possesses two bound electronic states. The ground 1A1 state has an equilibrium D3h structure and a vertical electron detachment energy VDE of 0. 66 eV. The 3E bound state pseudorotates through 3Al and 3B2 stationary points. The barrier for pseudorotation was found to be less than 0.002 eV at the QCISDT level. Two VDE peaks for the 3E anion were predicted to be at 0.45 and 1.15 eV, for transitions to the ground and the first excited state of the neutral, respectively. The ground state of the cation and the first three electronic states of the neutral Li3O were also considered and the vertical ionization potential for the ground neutral state was found to be 3.60 eV. Li3O and Li3O- are thermodynamically stable with respect to the unimolecular decompositions Li3O-o right arrow Li2O Li-o. Hence the species should be amenable to experimental studies.