https://en.wikibooks.org/wiki/Introduction_to_Inorganic_Chemistry/Ionic_and_Covalent_Solids_-_Structures
CdI2 structure is much more common than the CdCl2 structure. CdCl2 structure: MCl2 (M = Mg, Mn, Fe, Co, Ni, Zn, Cd) NiBr2, NiI2, ZnBr2, ZnI2 CdI2 structure: