Interpretation of apparent thermal conductivity in finite systems from equilibrium molecular dynamics simulations

Abstract

We propose a way to properly interpret the apparent thermal conductivity obtained for finite systems using equilibrium molecular dynamics simulations (EMD) with fixed or open boundary conditions in the transport direction. In such systems the heat current autocorrelation function develops negative values after a correlation time which is proportional to the length of the simulation cell in the transport direction. Accordingly, the running thermal conductivity develops a maximum value at the same correlation time and eventually decays to zero. By comparing EMD with nonequilibrium molecular dynamics (NEMD) simulations, we conclude that the maximum thermal conductivity from EMD in a system with domain length 2L is equal to the thermal conductivity from NEMD in a system with domain length L. This facilitates the use of nonperiodic-boundary EMD for thermal transport in finite samples in close correspondence to NEMD.

arXiv comment7pages, 8 figures

References in corpus (13)

• Optimized Tersoff and Brenner empirical potential parameters for lattice dynamics and phonon thermal transport in carbon nanotubes and graphene
• Molecular dynamics calculation of the thermal conductivity of vitreous silica
• Phononic thermal properties of two-dimensional materials
• Force and heat current formulas for many-body potentials in molecular dynamics simulation with applications to thermal conductivity calculations
• Efficient molecular dynamics simulations with many-body potentials on graphics processing units
• Structural, electronic, and transport properties of silicon nanowires
• Kapitza resistance at the liquid solid interface
• Influence of Boundaries and Thermostatting on Nonequilibrium Molecular Dynamics Simulations of Heat Conduction in Solids
• Thermal conductance at the interface between crystals using equilibrium and non-equilibrium molecular dynamics
• Equivalence of the equilibrium and the nonequilibrium molecular dynamics methods for thermal conductivity calculations: From bulk to nanowire silicon
• A minimal Tersoff potential for diamond silicon with improved descriptions of elastic and phonon transport properties
• Heat current anticorrelation effects leading to thermal conductivity reduction in nanoporous Si
• Non-local linear-response functions for thermal transport computed with equilibrium molecular-dynamics simulation

Cited by in corpus (2)

• GPUMD: A package for constructing accurate machine-learned potentials and performing highly efficient atomistic simulations
• Exactly equivalent thermal conductivity in finite systems from equilibrium and nonequilibrium molecular dynamics simulations