Testing thermal conductivity models with equilibrium molecular dynamics simulations of the one-component plasma

B Scheiner and SD Baalrud, PHYSICAL REVIEW E, 100, 043206 (2019).

DOI: 10.1103/PhysRevE.100.043206

Equilibrium molecular dynamics simulations are used to calculate the thermal conductivity of the one- component plasma via the Green-Kubo formalism over a broad range of Coulomb coupling strength, 0.1 <= Gamma <= 180. These simulations address previous discrepancies between computations using equilibrium versus nonequilibrium methods. Analysis of heat flux autocorrelation functions show that very long (6 x 10(5) omega(-1)(p)) time series are needed to reduce the noise level to allow less than or similar to 2% accuracy. The simulations provide accurate data for Gamma less than or similar to 1. This enables a test of the traditional Landau-Spitzer theory, which is found to agree with the simulations for Gamma less than or similar to 0.3. It also enables tests of theories to address moderate and strong Coulomb coupling. Two are found to provide accurate extensions to the moderate coupling regime of Gamma less than or similar to 10, but none are accurate in the Gamma greater than or similar to 10 regime where potential energy transport and coupling between mass flow and stress dominate thermal conduction.

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