The semiclassical and quantum-classical approaches to elementary surface processes: dissociative chemisorption and atom recombination on surfaces

In recent decades, theoretical techniques known in gas-phase scattering theory and quantum chemistry have been extended and applied to the interactions of atoms/molecules with surfaces. As a consequence, due also to the accessibility of powerful computational resources, great progress has been made in the atomistic simulation of molecular surface processes. The complexity of the effects and phenomena that have to be taken into account remains, however, high and is generally not fully tractable even for elementary surface processes. Consequently, the dynamics of heterogeneous systems is treated with different collisional schemes to different degrees of accuracy. In particular, within the semiclassical collisional approach, some of the most important features of the molecule-surface interactions can be treated quite accurately, including the energy-exchange mechanisms between the adsorbate and the substrate.