High-energy optical absorption in f-compounds

Over a large energy domain, the electronic spectra of f-compounds arise mainly from three types of electronic transitions: image transitions, image transitions and ligand to metal charge transfer. The first transitions can be predicted quite successfully via an empirical Hamiltonian exploiting the symmetry of the system under consideration and evaluating the radial dependence of the various interactions felt by the f-electron through adjustable phenomenological parameters. The two other electronic transitions can be modelled via the refined spin pairing theory. Both similarities and differences in chemical and spectroscopic behavior of lanthanides and actinides will be briefly discussed.