Lifetimes of Levels in the Spectra of Xeon-like Lanthanum (La IV)

We calculated the energy levels, Lunde g-factors and lifetimes for the 5p6, 5p5nf = 4, 5), 5p5ns (n =6, 7, 8), 5 p'np (n-6, 7), and 5p'nd- 5, 6) excited levels of xenon-like lanthanum (La IV, Z = 57). These calculations have bccn carried out by using the relativistic Hartree-Pock (IIFR) method developed by Cowan. We compared the results with previously reported the available calculations and experiments in literature. A discussion of these calculations for La IV in this study has also been in view of the I-IFR method.