VERTICAL ELECTRON DETACHMENT ENERGIES FOR OCTAHEDRAL CLOSED-SHELL MULTIPLY-CHARGED ANIONS

The local stability of several octahedral species AlF63-, GaF63-, InF63-, TlF63-, TaF6-, ZrF62-, LaF63-, and LaCl63- was studied by using ab initio methods. All systems were found to have minima at octahedral geometries. The electronic stability of these species was considered by using electron propagator theory (EPT) and the Moller-Plesset (MP) perturbation scheme. The results indicate that triply-charged molecular species may be electronically stable in the gas phase. Due to the slow convergence of the EPT and MP series and limitation in our one-electron basis set, the final conclusion requires a more advanced theoretical treatment. The doubly- (ZrF62-) and singly-charged (TaF6-) species were found to possess very high electronic detachment energies of 5.0 and 10.6 eV, respectively. TaF6- is predicted to be thermodynamically stable and ZrF62- slightly unstable with respect to the unimolecular decomposition ML(6)(n-) --> ML(5)((n-1))(-) + L(-).