Comparison of atomic-level simulation methods for computing thermal conductivity

We compare the results of equilibrium and nonequilibrium methods to compute thermal conductivity. Using Sillinger-Weber silicon as a model system, we address issues related to nonlinear response, thermal equilibration, and statistical averaging. In addition, we present an analysis of finite-size effects and demonstrate how reliable results can be obtained when using nonequilibrium methods by extrapolation to an infinite system size. For the equilibrium Green-Kubo method, we show that results for the thermal conductivity are insensitive to the choice of the definition of local energy from the many-body part of the potential. Finally, we show that the results obtained by the equilibrium and nonequilibrium…

• OO
  Office of Science
• DO
  Division of Chemistry