The existence and stability of the anions matching the formula (M = Li, Na, K, Be, Mg, Ca, B, Al, Ga)

The electronic stabilities of the MF k + 2 - anions (where M = Li, Na, K, Be, Mg, Ca, B, Al, Ga; and k is the maximal formal valence of atom M) were investigated at the OVGF/6-311 + G(3df) level. The vertical electron detachment energies (VDE) of the anions examined were found to be large (7.1–10.1 eV) albeit not significantly exceeding those for the corresponding MF k + 1 - superhalogen anions. Even though all the MF k + 2 - species studied were predicted to be both geometrically and electronically stable, some of them turned out to be thermodynamically unstable (i.e., susceptible to the F atom loss).