Tris(glycine) calcium(II) dibromide single crystal has been irradiated with aγ-source to produce free radicals and the irradiated sample has been subjected toepr studies. The observed spectra reveal that an NH₄ radical is formed by rupturing glycine molecule due to irradiation. The unpaired electron is localized on the C-N bond. The proton hyperfine interaction on the unpaired spin shows orthorhombic symmetry and the spectroscopic splitting factor remains isotropic.

epr measurements on kainite containing Mn²⁺ impurities are made at x-band microwave frequencies at room temperature. The fine structure transitions observed inac* plane have helped to extract the spin Hamiltonian parameters of Mn²⁺ ions in the crystalline environment. The results indicate strong orthorhombic crystalline field and the rhombic field parameter is larger than those observed in the other similar systems. The z-axis of the D-tensor is determined with respect toac* plane by theoretically fitting the experimental fine structure transitions.