The existence and stability of the anions matching the MFk+2- formula (MÂ =Â Li, Na, K, Be, Mg, Ca, B, Al, Ga)

► The MFk+2- (M = Li, Na, K, Be, Mg, Ca, B, Al, Ga) anions possess VDE = 7.1-10.1 eV. ► The VDEs of MFk+2- are slightly larger than those of the corresponding MFk+1- anions. ► The largest excess electron detachment energy (10.1 eV) was estimated for GaF5-. ► Certain MFk+2- anions were found to be thermodynamically unstable.