Energy Levels of Ho3+ in LaCl3

A least-squares fit of the previously assigned J levels of Ho3+ in LaCl3 combined with a crystal-field calculation for the upper levels has made possible the assignment of many of the levels above 28 000 cm−1 observed by Dieke and Pandey. A final least-squares fit of 23 J levels, with the inclusion of configuration interaction, gave an rms deviation of 68 cm−1 with the parameter values E0=20 770, E1=6682.6, E2=30.69, E3=620.1, ζ=2127.1, α=23.5, β=−811.2 cm−1. The crystal-field parameters resulting from a fit of 81 components of the 5I4,5,6,7,8 and 5F2,3,4,5 levels are B20=113.6, B40=−33.9, B60=−27.8, and B66=276.7 cm−1. The rms deviation in this case was 2.0 cm−1. These crystal-field parameters give a satisfactory prediction of the crystal-field splitting of most of the excited J levels.