The dielectric loss of the crystals CsI + Ca2+, CsI + Sr2+ has been studied. Their dielectric loss curves show only one peak for each temperature. The temperature dependence of “peak frequency” obeys an “Arrhenius relation” and thus the energies E for the reorientation of complexes may be determined. In both crystals, CsI + Ca2+ and CsI + Sr2+, the values of E are the same. The latter result is theoretically discussed.