Energy level analysis of Pm3+:LaCl3

A diagonalization of the matrices representing the combined atomic and crystal-field interactions for the 4f4 configuration has provided the basis for interpreting the spectrum of Pm3+:LaCl3. Experimental data were drawn from the literature and were augmented by unpublished absorption and fluorescence results. A method of truncating the large matrices involved is discussed and shown to yield results in excellent agreement with complete calculations. Use of fluorescence branching ratio calculations based on the Judd--Ofelt intensity theory to monitor the interpretation of fluorescence spectra is discussed