Collision-induced spectra at a gas-solid interface

In analogy with collision-induced translational absorption in the far infrared in binary mixtures of inert gases, it is suggested that a similar process mustoccur at a gas-solid interface. Each gas molecule develops a dipole moment that depends on its distance from the surface, and its time dependence due to the thermal motion of the molecule should cause optical activity. The necessary theory and expected absorption curves for a typical model are given: