An ab initio study on MgX3- and CaX3- superhalogen anions (X = F, Cl, Br)

The vertical electron detachment energies (VDEs) of twenty MX3- (M = Mg, Ca; X = F, Cl, Br) anions were calculated at the OVGF level with the 6-311 + +G(3df) basis sets. The largest vertical electron binding energy was found for MgF3- system (8.793 eV). All negatively charged species possess the VDEs that are larger than 5.9 eV and thus may be termed superhalogen anions. The strong dependence of the VDE of the MX3- species on the ligand-central atom (M-X) distance and on the partial atomic charge localized on Mg or Ca was observed and discussed, as well as the other factors that may influence the electronic stability of such anions. (C) 2003 Elsevier Science B.V. All rights reserved.