The dependence of the J energy level position with the crystal field

In order to reduce the discrepancies in the crystal field analyses of the 4fN configuration was used second order perturbation theory without approximation. The even and odd parts of the Hamiltonian crystal field causes shifts in J level mean energy that depend on the crystal field strength and polarizability of the Ln3+ ion, respectively. This analysis is independent of the applied coupling scheme. The prediction found was used for investigate the variation of the local structure of the Eu3+ ions in glass.