Abstract

The chemical evolution of LiH and LiH+ molecules, possibly formed during the recombination era of the early universe, is usually considered in reactions with H and H+, the latter species being some of the most abundant partners under the above conditions. The quantum method selected in the present work, the negative imaginary potential (NIP) method, is described in great detail and tested in comparison with other methods for various simple reactions. The results show the numerical validity of the NIP approach and confirm our earlier findings on the specific outcomes for lithium reactions of the early universe.