Role of Rotational Motion in the Dissociative Adsorption and Associative Desorption Dynamics of $D_2$/Cu(111)

We point out the importance of the incidence energy of ${\mathrm{D}}_2$ to account for the nonmonotonic behavior of the adsorption probability of ${\mathrm{D}}_2$/Cu(111) as a function of its initial rotational state. We then show that a very prominent initial cooling, a mild heating, and then a final cooling of the rotational temperature with respect to the surface temperature, for increasing rotational energies, should be observed for the desorption of ${\mathrm{D}}_2$ from Cu(111). We finally show that the desorption results could be consistently connected with the adsorption probability data.