Investigations of the EPR Parameters and Local Lattice Structure for the Rhombic Cu2+ Centre in TZSH Crystal.

The electron paramagnetic resonance (EPR) parameters [i.e. g factors g _i ( i= x, y, z) and hyperfine structure constants A _i] and the local lattice structure for the Cu²⁺ centre in Tl₂Zn(SO₄)₂·6H₂O (TZSH) crystal were theoretically investigated by utilising the perturbation formulae of these parameters for a 3d⁹ ion under rhombically elongated octahedra. In the calculations, the admixture of d orbitals in the ground state and the ligand orbital and spin-orbit coupling interactions are taken into account based on the cluster approach. The theoretical EPR parameters show good agreement with the observed values, and the Cu²⁺-H₂O bond lengths are obtained as follows: R _x≈1.98 Å, R _y≈2.09 Å, R _z≈2.32 Å. The results are discussed. [ABSTRACT FROM AUTHOR]