  We combine Creutz energy conservation with Kawasaki spin exchange to simulate
the microcanonical dynamics of a system of interacting particles. Relaxation
occurs via Glauber spin-flip activation using a self-consistent temperature.
Heterogeneity in the dynamics comes from finite-size constraints on the spin
exchange that yield a distribution of correlated regions. The simulation
produces a high-frequency response that can be identified with the boson peak,
and a lower-frequency peak that contains non-Debye relaxation and non-Arrhenius
activation, similar to the primary response of supercooled liquids.
