Free-Ion and Crystalline Spectra of Pr3+ (Pr IV)

Abstract

The spectrum of the free tripositive praseodymium ion (Pr IV) has been obtained under high resolution between 1200 Å and the infrared. The analysis has yielded all 49 levels of the four lowest configurations 4f2, 4f5d, 4f6s, 4f6p. A comparison with the crystal levels of Pr3+ in various lattices shows a depression of up to 5% in the anhydrous chlorides.