DFT calculations of crystal-field parameters for the lanthanide ions in the LaCl3 crystal

We present herein a calculation of crystal-field (CF) parameters for the lanthanide ions in the LaCl(3) crystal, using the density functional theory-based orbital-free embedding formalism in conjunction with the effective Hamiltonian method. The calculated values for the second- and fourth-rank CF parameters agree fairly well with the experimental data. It is found that the effect of ligand polarization plays a crucial role in determining the sign and magnitude of the second-rank CF parameters, while the effect of Pauli repulsion between 4f electrons and the ligands is important for the fourth-rank CF parameters. The usefulness of the present approach is illustrated by a study of the relative preference of Eu(3 + ) occupation on the two distinct Pb(2 + ) sites in the KPb(2)Cl(5) crystal. The computational approach and results discussed in this work are useful for a better understanding and simulation of the CF effect in the lanthanide-containing systems.