Intraconfigurational transitions in tetrahedral d2 ions: on the expediency of the ligand field model for transition metal ions in high-oxidations states Original Research Article

A ligand field analysis of intraconfigurational transitions in tetrahedral MnO43− and FeO43− is shown to give rather anomalous B values for the ground state configuration e2. A model taking explicit account of interactions between d2 (ionic) multiplets and singly excited (ligand to metal) charge transfer configurations is used to show that for low charge transfer energies each state of e2 is modified to a different extent by covalency effects. A full account of all possible charge transfer excitations in comparison with published spectral data allows to deduce a rather important electrostatic component to the multiplet splittings originating from the e1t21 (strong field) configuration. This is drawn as an explanation for the considerable success of the ligand field model in describing term energies belonging to such a configuration.