2001A&A...372.1083B

Collision strengths and collisional rate parameters have been calculated for transitions among 92 n=2 and n=3 levels of O-like Fexix. The method used is the Breit-Pauli R-matrix formalism in which most prominent relativistic effects are accounted for. Partial wave contributions up to J=59/2 are included explicitly while ``top-up'' procedures complete the sum to infinity. Several thousand energy points were used to fully incorporate the effect of resonances in the collisional cross sections when estimating the collisional rate parameters. This is particularly important at lower temperatures where the resonant contributions dominate. The present results are expected to be accurate to better than 20% for transitions among n=2 levels.