Computed distributions of rotovibrational transitions in LiH(X(1)Sigma(+)) and LiH+(X(2)Sigma(+))

Accurate potential energy curves for the ground electronic states of LiH and LiH+ are employed to generate vibrational and rotational levels over a broad range of J values for both systems. The corresponding dipole functions are computed and used to obtain the frequency and intensity distributions of all relevant transitions between bound states for pure vibrational excitations, pure rotational excitations and for dipole allowed rovibrational processes. This extensive set of absorption data for both molecules is employed to locate the most likely region in the infrared spectrum where characteristic lines could be observed. Such data should be useful in experimental attempts to search for LiH and LiH+ lines at high redshifts. We found that transitions between ionic levels will be markedly less intense than those for the neutral system and that transitions between rotationally 'hot' levels will be markedly more intense than those between low-J levels.