Breit-Pauli energy levels, transition probabilities, and lifetimes for 3d⁵ levels in Fe IV of astrophysical interest

Energy levels, lifetimes, and transition probabilities for transitions between computed levels of 3d^5 of Fe IV are reported. The E2 and M1 transition probabilities are compared with earlier theoretical results, often only the values published by Garstang in 1958. From the available astronomical observations of optical emission lines arising from the same level, a few direct tests are now possible and they show consistency with the theoretical calculations.