The electronic structures of the Cl3−, Br3−, I3−, BrCl2−, BrI2−, BrICl−, and BrII− anions were calculated using the discrete variational Xα method. These calculations showed that the adiabatic electron affinity (EA) of the corresponding trihalogen molecules is close to the vertical EA and first vertical ionization potential (IP) of the corresponding singly charged anions. The calculated first IP of all these anions are rather similar (3.3–3.8 eV). Thus, these trihalides may be considered “weak” superhalogens.