Electron capture in slow collisions of O6+ ions with atomic hydrogen

Aims . Electron capture in collisions of highly charged O6+ ions with ground-state hydrogen atoms is a very important process in solar wind X-ray studies.Methods . In the present study, the full quantum-mechanical molecular-orbital close-coupling method is employed to study electron capture reactions in collisions of O6+ ion with ground-state atomic hydrogen in the energy region from 10−4 keV u−1 to 5 keV u−1 . The ab initio multi-reference single- and double-excitation configuration interaction (MRD-CI) method is used to calculate the potential and coupling data used in the QMOCC calculations.Results . Total and state-selective cross sections for the dominant and subdominant reaction channels are calculated and compared with the available experimental and theoretical data. The branching ratios for Lithium-like O5+ excited ions are used to calculate the contribution of cascade radiative transitions from n  = 5 levels to the population of 4l states. From the calculated cross sections, reaction rate coefficients are obtained for temperatures between 1000 and 1 × 109 K and compared with other calculations.