J.R. Manson

CLEmson University

Department of Physics & astronomy

Scattering of small molecules by surfaces

 Cardwell 102

Tuesday, October 4, 2005

4:30 p.m.


          Scattering molecules from surfaces is one method of obtaining information about specific aspects of the molecule-surface interaction potential and about the exchange of energy between the various molecular degrees of freedom and the modes of surface excitation.  Scattering experiments can also probe surface trapping and sticking and the initial precursors to chemical reactions.  Many such experiments have been carried out using molecules with masses significantly heavier than hydrogen for which the translational and rotational degrees of freedom during the collision process can be approximated by classical mechanics.  Described in this talk is a mixed classical-quantum theory of molecule-surface scattering that treats the translational and rotational motion of the molecule and the multiphonon excitation of the surface with classical mechanics while the internal molecular vibrational degrees of freedom are treated semiclassically.  Comparisons of calculations with recent experiments show that such a theory can be useful in explaining observed scattered angular distributions, translational energy-resolved spectra, energy transfer to molecular rotational modes, and excitation probabilities for internal vibrational modes.