Calculating thermal conductivity in a transient conduction regime: theory and implementation

We present a molecular dynamics method addressed to the calculation of the latticethermal conductivity during the transient regime of approach to equilibrium from aninitial condition of nonuniform temperature profile. We thoroughly assess the basics, therobustness, and the accuracy of the method, in particular by showing that its results arebasically independent of most of the arbitrary simulation parameters. In addition, themethod here presented is computationally light, thus paving the way for the investigationof large systems. This feature is fully exploited to investigate the thermal transportproperties of disordered and nanostructured silicon samples, providing a clear atomisticpicture on the ability of grain boundaries and lattice disorder to affect thermalconductivity by improved scattering of vibrational modes with long mean free path.