ENERGY-LEVELS OF TERBIUM(III) IN THE ELPASOLITE CS2NATBF6

Polarized two-photon excitation (TPE) and emission spectra are present ed for terbium(III) in the elpasolite Cs2NaTbF6. Almost 90 levels of u nambiguous symmetry have been assigned up to 35 000 cm(-1) with the ai d of a one-electron crystal held Hamiltonian. This represents the most complete and extensive data set so far reported for a lanthanide ion at a cubic site. Large deviations from the predictions of the one-elec tron crystal field model are observed in the splitting of a number of multiplets. These are discussed in terms of the correlation crystal fi eld (CCF).