A new class of smooth and structured solid models is developed from the generalized Langevin theory of gas/solid processes [S. A. Adelman and J. D. Doll, J. Chem. Phys. 64, 2375 (1976)], and numerical results for scattering off the simplest of these model solids are presented. The models, which may be refined to arbitrary precision, allow one to treat the many-body or lattice effect in gas/solid dynamics in a qualitatively correct but computationally simple manner. Scattering calculations based on the models may be carried out using standard classical trajectory methodology; the many-body dynamics modifies the usual classical equations of motion through noise terms and auxiliary variables. Collisional studies based on the simplest of the new models reveal the importance of many-body dynamics on energy transfer and trapping thresholds. The percentage of energy transfer due to many-body effects is found to be a rapidly increasing function of solid Debye temperature ΘD; at ΘD≳ 225°K the many-body contribution to energy transfer often exceeds the uncoupled oscillator contribution. The threshold energy for trapping on the simplest model solid is often more than doubled due to many-body influence. Finally, helium scattering from silver is simulated and the results are compared with the measurements of Sau and Merrill.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry