Low-frequency excitations in glassy selenium: A comparison of neutron-scattering and molecular-dynamics results.

The microscopic low-frequency dynamics of glassy selenium is investigated by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms of intraand interchain processes is achieved from the analysis of the simulation results. The S(Q, E) dynamic structure factors are analyzed in terms of the frequency moments or from a model scattering law, and the wave-vector dependence of the relevant quantities is established. Finally, the anomalous behavior of the heat capacity at moderately low temperatures is shown to be originated by mostly interchain interactions.