Forbidden Transitions in 3p4and 4p4Configurations

We have calculated energy levels and radiative transition probabilities in the ground configurations of the sulfur and selenium isoelectronic sequences up to molybdenum and silver, respectively. Transition probabilities have been obtained for M1 and E2 "forbidden lines" within the p 4 configurations using electrostatic and spin-orbit integrals for the interactions within this configuration deduced by a fitting procedure to the available experimental energy levels or by graphical inter(extra)polation of Slater parameters along the sequence when the energy levels are unknown. Some of the most important configuration interaction and relativistic effects have been included explicitly using the HFR self-consistent method due to Cowan and Griffin. For most of the ions in the selenium sequence, transition probabilities are reported for the first time. The effects of including configurations with 4 f electrons explicitly have been studied for both the 3 p 3 and 3 p 4 configurations.