The internal energy excitation and relaxation of oriented G, G', and T rotamers of 1-bromo-2-chloroethane colliding with a model surface were studied by classical molecular dynamics. For a given oriented molecule colliding with a surface at an incident angle, the distributions of the final rotational, vibrational, and conformational energies of the rotamers were calculated over the accessible thermal energies from room temperatures to approximately 600 K. The asymmetry in the conformational energies of the G and G' optical rotamers is specifically examined. The mechanism of the phenomenon of chirality generation through oriented-molecule/surface collisions, recently observed in this laboratory, is discussed. (C) 2011 Elsevier B.V. All rights reserved.