‘Weak-field’ ligand-field calculation for tetragonally distorted d2 and d8 systems

Abstract

The d² and d⁸ crystal-field calculation of Ballhausen and Liehr has been extended to include tetragonal distortion. Trees correction, and all off-diagonal spin–orbit coupling and crystal-field matrix elements. Parameters used are evaluated and a minimum set selected. Those features of the calculation capable of experimental verification and use are emphasised. The calculation is used to predict as accurately as possible the spectra of tetragonally distorted nickel(II) systems.