Hyperfine Structure of the Spectrum of Pr II

Analysis of the hyperfine structure of the term 4 f 3 ( 4 I )6 s of Pr II resulted a (6 s )=0.426 cm -1 , a 4 f =0.0227 cm -1 . From the value of a (6 s ) the nuclear magnetic moment of Pr was deduced to be µ=+4.0 n.m., in agreement with the value given in the literature. From the value of a 4 f the screening constant σ of the 4 f electron was deduced to be 32.9. The quadrupole moment of Pr was found to be Q =(0.0±0.2)×10 -24 cm 2 . This is in agreement with the value Q =-0.05×10 -24 cm 2 calculated from the data published by Lew regarding the hyperfine structure of the ground term of Pr I.