Electronic Energy Levels of the Trivalent Lanthanide Aquo Ions. III. Tb3+

A total of 23 experimental “free-ion” energy levels of Tb3+ (aquo) have been fit with an rms deviation of 56 cm−1. The resulting parameters are: E1 = 6021.5, E2 = 29.030, E3 = 608.54, ζ4f = 1709.5, α = 20.131, β = − 370.21, and γ = 1255.9. The latter three parameters arise from including the effects of configuration interaction in the calculation. Assignments were based upon a correlation between calculated and observed band intensities at energies up to ≈40 000 cm−1.