A theoretical study of the positive and dipositive ions of M(NH3)n and M(H2O)n for M = Mg, Ca, or Sr

The structure and binding energies are determined for many of the M(H2O)n(+) and M(H2O)n(2+) species, for n = 1-3 and M = Mg, Ca, or Sr. The trends are explained in terms of metal sp or sd-sigma hybridization and core polarization. The M(NH3)n(+) systems, with M = Mg or Sr, are also studied. For the positive ions, the low-lying excited states are also studied and compared with experiment. The calculations suggest an alternative interpretation of the SrNH3(+) spectrum.