Spectrum of Doubly Ionized Lanthanum (La iii)

Forty-five spectral lines of doubly ionized lanthanum in the interval from 700 to 2000 Å are reported. Thirteen newly discovered terms of the ns, np, nd, nf, and ng series are given. Calculations of the limit of three of these series result in a value of 154 672 cm−1 for the ionization energy with an estimated uncertainty of ±10 cm−1.