PARTITION-FUNCTIONS FOR 3RD SPECTRA OF THE LANTHANIDES

Partition functions are calculated for the third (i.e., doubly-ionized ) spectra of the lanthanide rare earths for temperatures generally in the range 7000-30 000 K. The atomic-structure code of Cowan is used to predict energy levels for all terms based on the relevant low electro n configurations. Observed energy levels are used to adjust the Slater parameters. Interpolation formulae are given to allow rapid evaluatio n of the partition functions for any temperature within the ranges of validity.