3s23p-3s3p2 transitions in SIV

We use both the civ3 and mchf codes to calculate oscillator strengths of allowed and intercombination lines in the 3s(2) 3p-3s3p(2) multiplets. Valence, core-valence and some core-core correlation effects are included. The two approaches give results in excellent agreement. Core effects are particularly important for the intercombination lines, though relatively minor for allowed transitions. We obtain a branching ratio of 1.42 with an estimated accuracy of 0.02 for the transitions, compared with an experimental value of 1.12+/-0.1. The A -values of the intercombination lines are substantially different from those of previous calculations.