Multipole transitions in nickel-like and palladium-like spectra

The relative magnitudes of the electric multipole (E1, E2, E3) and magnetic multipole (M1, M2 and M3) radiative decay rates, calculated by the fully relativistic multiconfiguration Dirac - Fock (MCDF) approach, have been compared for all the transitions involving the lowest 17 or 37 levels of highly ionized nickel-like and palladium-like ions, respectively. The importance of the E3 and E2 contributions to the decay processes of the highest ionization stages along the Ni and Pd sequences is underlined. The respective merits of the pseudo-relativistic Hartree - Fock (HFR) and of the MCDF techniques are compared in the case of E1 radiation emitted by uranium ions.