Microscopic analysis of 5d states splitting and charge transfer energies dependence on interionic distance in alkaline earth fluorides doped with light trivalent lanthanides

A first principles fully relativistic analysis (K. Ogasawara et al., Phys. Rev. B 2001, 64, 115413) of the dependence of 5d orbitals splitting (10Dq) and charge transfer (CT) energies on interionic distance has been performed for light lanthanides (Ce3+, Pr3+, Nd3+) in CaF2, SrF2, BaF2 crystals. The salient feature of the method is that four-component molecular orbitals (MO) composed of atomic wave functions are used as the basis set. Without any fitting parameter, the power dependencies for 10Dq and linear dependencies for the CT energies on the distance between rare-earth (RE) ions and ligands were obtained. A comparison with experimental values is discussed.