Energy Levels of Pr3+ in Various Crystal Hosts

Abstract

The results of a least squares fit of the energy levels of Pr³⁺ in various crystal hosts are reported. By using an expanded eight‐variable semiempirical free‐ion Hamiltonian, the average deviation between the calculated and observed levels was reduced by an order of magnitude from the average deviation found using the usual four‐variable free‐ion Hamiltonian. The best fit parameters $F_2{\mathrm{\prime ,\; F}}_4{\mathrm{\prime ,\; \zeta }}_{\text{4f}}\mathrm{\prime ,\; \alpha \prime ,\; \beta \prime ,\; \gamma \prime }$ , and $M^0\prime$ determined for various crystal hosts are reported. In addition the magnitudes of the configuration interaction screening factors of the $\text{4f}$ interelectric Coulombic $F_2{\mathrm{,\; F}}_4$ , and $F_6$ integrals are presented. The effects of the crystalline hosts on the empirical parameters are examined. It is suggested that changes in the various screening factors involved in the expanded free‐ion Hamiltonian may be responsible for sizable contributions to the over‐all host effects on the empirical parameters.