Studies of the optical band positions and EPR g factors for Cu(H2O)62+ centers in Tutton salt crystals

► Optical band positions and g factors of M2Cu(SO4)2·6H2O (M = NH4, Rb) are calculated. ► The calculation is based on complete diagonalization (of energy matrix) method. ► The calculation shows that the superposition model is valid. ► Defect structures of Cu2+ centers in M2Zn(SO4)2·6H2O are studied.