Transition probability calculations for (open-shell) atoms have shown that large wave function expansions are often needed to obtain sufficient accurate results. For ab-initio calculations, these wave functions must include the effects of relativity, electron correlations, and the rearrangement of the electron density within a common framework. The REOS99 program accounts for all of these effects for the computation of Einstein coefficients, oscillator strengths, and (radiative) lifetimes. It applies relativistic wave functions from the GRASP92 package [2] which need subsequently to be expanded into a determinant basis [3] in order to apply them to REOS99 (Source: