The Pseudocontact Shift for a $3d^9$ System in a Strong Crystal Field Environment of Tetragonally Distorted Tetrahedral Symmetry

The Pseudocontact Shift for a $3d^9$ System in a Strong Crystal Field Environment of Tetragonally Distorted Tetrahedral Symmetry

A general expression adopting a nonmultipole expansion method is derived for pseudocontact contribution to the NMR chemical shift arising from the electron orbital angular momentum and electron spin dipolar-nuclear spin angular momentum interaction of $3d^9$ system in a strong crystal field of tetragonally distorted tetrahedral symmetry. From this expression all the multipolar term are determined and the exact solution of ${\Delta}$B/B(ppm) is compared with the multipolar term. The $1/R^5$ term in the multipolar terms contributes dominantly to the NMR chemical shift but the other terms are certainly significant except that of the <111> axis. In addition, an analysis of the temperature dependence of the NMR chemical shift further illustrates that considerable care must be taken in interpeting NMR results in paramagnetic system.