Quantum mechanical scattering calculations for chargeexchange: O + H+ ↔ O+ + H

Abstract

Thermal energy collisions of oxygen atoms with protons (O + H+) maylead to fine-structure excitation of the oxygen or to charge exchange (O+ + H).The reverse process, collisions of oxygen ions with hydrogen, may also lead tocharge exchange. Detailed quantum mechanical calculations of these processes arepresented here. The potential curves and coupling terms of 3Σ−symmetry used are those recently calculated by Spirko et al (2000 J. Phys. B: At. Mol.Opt. Phys. 33 2395–407). The other necessary potentials, the A 3Π and5Σcurves, were taken from the literature. Cross sections for charge exchange andfine-structure excitation are reported. For several transitions, mechanisms based oncurve crossings are proposed. The analysis indicates that the scattering cross sections aresensitive to the form of the molecular potentials for internuclear distances of 10– 15 a0.The only point of comparison with experiment is for rate constants for chargeexchange, averaged over fine-structure levels. The present results, as well as otherrecent calculations, lie within the large error bars of the limited experimentaldata.