Thermochemical Radii - Cations

Ionr(pm)
Cd(NH3)62+ 266
Co(H2O)62+ 234
Co(NH3)5Cl2+ 236
Co(NH3)62+ 260
Fe(NH3)62+ 263
Mg(H2O)62+ 235
Mn(H2O)62+ 234
Mn(NH3)62+ 265
NH4+ 137
N(CH3)4+ 201
Ni(H2O)62+ 229
Ni(NH3)62+ 258
PH4+ 157
Zn(H2O)62+ 235
Zn(NH3)62+ 264
Fr+ 172

Reference: Dasent, p. 78; H.D.B. Jenkins and K.P. Thakur, J. Chem. Educ., 56, 576 (1979).