Parametrisation and interpretation of paramagnetic ion spectra

Abstract
The essential similarity between interaction mechanisms for the 3dn, 4fn and 5fn series of paramagnetic ions in solids is emphasised. Some prevalent views of the relationship between parameter values and interaction mechanisms for 3dn ions are challenged. A unified model of the interaction processes is proposed and optimal parametrisation procedures for correlation crystal-field effects in 3dn ions are discussed.