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

The local stability of several octahedral species AlF63-, GaF63-, InF6 3-, TlF63-, TaF6-, ZrF62-, LaF63-, and LaCl63- was studied by using ab initio methods. All systems were found to have minima at octahedral g eometries. The electronic stability of these species was considered by using electron propagator theory (EPT) and the Moller-Plesset (MP) pe rturbation 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-electr on basis set, the final conclusion requires a more advanced theoretica l treatment. The doubly- (ZrF62-) and singly-charged (TaF6-) species w ere found to possess very high electronic detachment energies of 5.0 a nd 10.6 eV, respectively. TaF6- is predicted to be thermodynamically s table and ZrF62- slightly unstable with respect to the unimolecular de composition ML(6)(n-) --> ML(5)((n-1))(-) + L(-).