AbstractThe optical properties of EuF3and GdF3are reinvestigated. Crystal field parameters derived from the data by using the D3h→ C2vdescending symmetry procedure for EuF3are (in cm−1):B 02= 465,B 22= 375,B 04= −232,B 24= −96,B 44= −114,B 06= −490,B 26= 83,B 46= −518,B 66= −162. The temperature dependent paramagnetic susceptibility of EuF3, is calculated by using the simulated wave functions. The calculated and experimental paramagnetic susceptibi