Relativistic ab initio calculations of oscillator strengths and hyperfine structure constants in TlII

We present accurate calculations of oscillator strengths and hyperfine stru cture splitting for a set of transitions in Tl II, and discuss how they can be used in stellar atmosphere models of chemically peculiar stars. The res ults are in good agreement with recent experiments. The predicted uncertain ty for oscillator strengths ranges from about 5 to 20% and in most cases le ss than 10% for hyperfine structure constants.