Semiclassical wave packet studies of elastic and inelastic atom--surface scattering from a 3D model surface

Journal Article · Thu Aug 01 04:00:00 EDT 1985 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.449408· OSTI ID:5604889

Smith, C B; Raff, L M; Agrawal, P M

The semiclassical wave packet method for the investigation of elastic and inelastic gas--surface scattering is extended to the calculation of diffraction patterns and Debye--Waller factors for scattering from a three-dimensional surface. Application of the method to a model 3D surface yields energy transfer coefficients in good accord with our previous 2D semiclassical results and with the experimental molecular beam data. The calculated final-state momentum and energy distributions are highly structured and show that inelastic effects dominate the scattering process at high surface temperatures. At T/sub s/ = 300 K, the scattering is found to be more nearly elastic. The structural features of the distributions are shown to be correlated with the power spectrum for the lattice motion. Diffractive scattering is evident even at T/sub s/ = 1500 K. At T/sub s/ = 300 K, the diffraction is much more pronounced due to the increased elasticity of the collision and a larger Debye--Waller factor. The positions of the calculated diffraction peaks are found to be in excellent accord with that expected from the known surface grating and distribution of incident wavelengths. The dependence of the computed Debye--Waller factors upon T/sub s/, the surface Debye temperature and the gas-surface potential well depth is found to be accurately described by the simplified expressions developed by Beeby and by Comsa et al. In general, the method is shown to be well suited to the study of elastic and inelastic gas--surface processes.

• Research Organization: Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078
• OSTI ID: 5604889
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 83:3; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOM COLLISIONS
ATOMS
COLLISIONS
ELASTIC SCATTERING
INELASTIC SCATTERING
MECHANICS
QUANTUM MECHANICS
SCATTERING
SEMICLASSICAL APPROXIMATION
SURFACES