Ligand-field atomic-multiplet calculations for arbitrary symmetry

Abstract

We have developed a calculational method for ligand-field multiplets. In our method the effect of the perturbations surrounding the considered atom is described by a monoelectronic potential interacting with the external electrons and the Hamiltonian is obtained by summing all the intra-atomic interactions and the external perturbations at once. Our method does not require any assumptions regarding the hierarchy of interaction terms and can treat any geometry, even in the absence of any nontrivial symmetry group. We have applied this method to the case of nickel $2p$ edges in Ni-phthalocyanine and to study the experimental absorption spectra and magnetic circular dichroic reflectivity of a thin ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ film.