The free ion parameters obtained from a least-squares fit to the six lowest free ion levels of Nd3+ in CaWO4, neglecting configuration mixing, are (in cm-1): E1=4859.7, E 2=24.78, E3=482.0, and ζ=873.8. The rms deviation of this fit was 21. Crystal-field parameters appropriate to S4 symmetry were fit to the structure of the 4I9/2 and 4I11/2 levels. Intermediate coupling wavefunctions obtained from the free ion fit were used. J-J mixing between the 4I9/2 and 4I11/2 states was considered. The crystal-field parameter values found are (in cm-1): B02=514.2, B04=-1040.0, B 06=-60.0, B44=-1071.6, B 46=-980.0, B′44=16.4, and B′46= 13.1. The rms deviation of this fit was 9.5. We calculate the ground-state g values to be g∥=1.633 and g ⊥= 2.621. The corresponding experimental values are 2.035 and 2.537. By changing the Bmn we can get a better g-value fit, namely, 2.025 and 2.593.
