Crystal field interactions between Ce3+ion and fluoride ligands: a theoretical investigation

Superposition model (SM) analyses combined with ab initio calculations are presented to investigate crystal field interactions between Ce3+ ions and their fluoride ligands. On the basis of energies and wave functions derived from complete active space self-consistent field (CASSCF) embedded cluster calculations, 4f and 5d crystal field parameters (CFPs) for Ce3+ in three typical fluoride compounds (Cs2NaYF6, CaF2 and KMgF3) are extracted, showing a good agreement with available experimental data. Moreover, the SM intrinsic parameters, which are usually used to depict physical interactions between the dopant and its ligands, are determined from the ab initio calculated CFPs. The aim of this work is to obtain the quantitative dependence of intrinsic parameters on geometric structures around Ce3+ in fluoride compounds. Thus, the spectral parameters and further the spectroscopic properties of Ce-doped fluoride compounds would be conveniently predicted according to the calculations and analyses in the present work.