The Ionic Pathways of Lithium Chemistry in the Early Universe: Quantum Calculations for LiH+ Reacting with H

To better understand the overall role of lithium chemistry in the early universe, reactive quantum calculations involving LiH(+) have been carried out and rate coefficients have been obtained. The reactive quantum calculations have been performed using a negative imaginary potential method. Infinite-order sudden approximation and the coupled state approximation have been used to simplify the angular coupling dynamics. Rate coefficients are obtained from the reactive cross sections by further integration over Boltzmann distribution of velocities. The results from the present calculations suggest that, at low redshifts (z), LiH(+) should be amenable to observation as imprinted on the cosmic background radiation, in contrast with its neutral counterpart. At higher z, the ionic species may disappear through both depletion reaction and three-body break-up processes