Ligand Contribution to the Spin-Spin Anisotropic Hyperfine Interaction in the Tetragonal Cu2+ Complex Ion

Abstract

The nondiagonal, first‐order contributions to the hyperfine‐structure anisotropy of EPR spectra of the Cu²⁺(3d⁹) ion in tetragonal fields of O, N, S, F⁻, and Cl⁻ have been calculated. It is shown that such effects are comparable in order of magnitude with some of the effects due to orbital admixture. The ligand s and p_z contributions are computed separately and equations for the case of hybrid s–p_z orbitals are derived. Tables of values of the nondiagonal term as a function of the metal‐ligand distance are presented. Consideration of the nondiagonal contribution leads to larger values of the electron localization, as exemplified by five cases discussed in this paper.