Energy Levels, Wavelengths, and Transition Probabilities of Intercombination Lines in the Spectra of Gе-Like I, Cs, and La Ions

Energy levels, wavelengths, transition probabilities, and line strengths are calculated for the allowed electric dipole 4s 2 4p 2 –4s4p 3 and 4s 2 4p 2 –4s 2 4p4d transitions of Ge-like ions with Z = 53, 55 and 57, I XXII, Cs XXIV, and La XXVI. By employing active-space techniques to expand the confi guration list, we also include the Breit interaction and quantum electrodynamical (QED) effects to correct the atomic state wave functions and the corresponding energies. Both valence correlation and core polarization effects are included. The results are compared with the available experimental and other theoretical results.