On the eigenvectors of the g and A tensors of copper(II) substituted in sites of low symmetry

Abstract

When a paramagnetic ion is located in a low symmetry environment, the principal directions of the g and hyperfine tensors are by no means trivial. This situation occurs when a diamagnetic complex is doped with paramagnetic ions, particularly in the case of non isomorphism: The substitution will almost certainly induce some distortions of unknown magnitude. Obviously in these cases, it is important to reproduce by calculation not only the eigenvalues but also the eigenvectors. For this purpose, a computer program, recently written by A. Bencini and D. Gatteschi [1] is applied in the case of three copper(II) ESR studies (Cu(II) in bis(β-alanine) zinc(II) nitrate tetrahydrate [2], in cadmium(II) [3] and strontium(II) salicylate [4]. In the references [2–4] the g (or A) values were simply calculated along the experimental eigenvectors, assuming an idealized environmental symmetry. In the present note, the usefulness of calculated eigenvecors is stressed. Their knowledge may provide a supplementary case in favor of the substitution, as well as some appreciation of the magnitude of the distortion.