Analysis of the Third Spectrum of Praseodymium*

Abstract

The spectrum of doubly ionized praseodymium was recorded and analyzed, with the result that 118 energy levels of odd parity and 130 levels of even parity were derived. These include nearly all the levels of the 4f³, 4f²5d, 4f²6s, and $4f^{2}6\mathcal{p}$ configurations as well as some low levels of the 4f5d² and 4f²6d configurations. Electrostatic and spin–orbit parameters were determined for the 4f²6s configuration. From the hfs of the 4f²6s levels, a magnetic dipole interaction constant of 0.46 cm⁻¹ was obtained. An ionization potential of 23.2 V was calculated from levels of the 4f²6d and 4f²6d series.