Evaluation of momentum conservation influence in non-equilibrium molecular dynamics methods to compute thermal conductivity

To evaluate momentum conservation influence when using non-equilibrium molecular dynamics (NEMD) methods to compute thermal conductivity, the results of two kinds of NEMD methods, including the system momentum conserved and not, are compared in this work. Using argon crystal and the widely accepted Lennard–Jones interatomic pair potential as a model system, we find that the thermal conductivities calculated by the methods accord with each other within error. Therefore, whether the system momentum is conserved or not does not influence the results, and some unnecessary calculations can be avoided.