Non-equilibrium molecular dynamics simulations of the thermal transport properties of Lennard-Jones fluids using configurational temperatures
N Jackson and JM Rubi and F Bresme, MOLECULAR SIMULATION, 42, 1214-1222 (2016).
We investigate the accuracy of two expressions for configurational temperature when calculating thermal transport properties in non- equilibrium systems under thermal gradients. The temperature T-conF, introduced by Jepps et al. Phys. Rev. E. 62; 2000: 4757 is found to give results in almost exact agreement with the equipartition temperature for the thermal conductivity of the Lennard-Jones fluid, and for the temperature profile across a solid-liquid interface. Measurements of T-conF are, however, less precise than those of the equipartition temperature, which results in less accurate measurements of the interfacial thermal conductance across a liquid-vapour interface. The approximate expression T-con1, which depends strongly on the number of sampled atoms, predicts unphysical negative thermal conductances in liquid-vapour interfaces, highlighting the limitations of some definitions of the configurational temperature in the computation of thermal transport properties via non-equilibrium simulations.
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