Atomic data for transitions in Ar XVI and FeXXIV

Energy levels and radiative rates for E1, E2, M1, and M2 transitions among the lowest 24 levels, belonging to the n ≤ 5 configurations of Ar XVI and Fe XXIV, are calculated using the GRASP code. Collision strengths are also calculated over a wide energy range using the fully relativistic DARC code. Resonances are resolved in a fine energy mesh in the thresholds region and effective collision strengths are calculated for all 276 transitions at temperatures up to 107.7 K. Comparisons are made with the earlier available as well as other parallel calculations from the FAC code, and discrepancies are noted for some of the transitions in both ions.