4f(2)/4f6p configuration interaction in LiYF4:Pr3+

In two other papers [M. D. Faucher, O. K. Moune, D. Garcia, and P. Tanner, Phys. Rev. B 53, 9501 (1996); M. D. Faucher and O. K. Moune, J. Alloys Compounds (to be published)], it was shown that the introduction of the 5f(n)/5f(n-1)7p (or 4f(n)/4f(n-1)6p) configuration interaction eliminated large discrepancies in the crystal-field analysis of (i) U4+ (5f(2)) in Cs2UBr6 and Cs2ZrBr6, for which the least root-mean-square deviation between experimental and calculated energy levels falls down from 241 to 56 cm(-1), and (ii) Nd3+ in Nd2O2S, for which the discrepancy of the H-2(2)(11/2) level is eliminated by the configuration interaction with the excited 4f(2)6p configuration. The demonstration is now extended to Pr3+ and seems to be of general application. For LiYF4:Pr3+ the mean deviation is divided by more than 2 by utilizing an interaction matrix including 4f6p in addition to the ground configuration 4f(2).