Theoretical studies of the local structure and spin Hamiltonian parameters for Rh2+:ZnWO4

By establishing the perturbation formulas of the spin Hamiltonian parameters (anisotropic g factors and hyperfine structure constants) for a rhombically compressed 4d7 cluster, the EPR spectra and local structure are theoretically investigated for Rh2+:ZnWO4. Due to the Jahn-Teller effect, the impurity center shows slight axial compression of about 0.002 nm along the Z-axis and the perpendicular angular variation of about 6° for the planar impurity-ligand bonds. These lattice deformations transform the significant elongation (by about 0.031 nm) of host Zn2+ site into slight compression in the impurity center. The local distortion of the Jahn-Teller nature is discussed.