Open Systems out of Equilibrium: Theory and Simulation

TL;DR

This paper adapts the Bergmann and Lebowitz theoretical model for open, out-of-equilibrium systems into the adaptive resolution molecular dynamics technique, enabling accurate simulations of open systems with thermal gradients.

Contribution

It introduces a novel translation of a classical theoretical model into a practical simulation method for open, out-of-equilibrium systems.

Findings

Excellent agreement with larger, closed system simulations.

Validates the adaptive resolution method for open systems.

Enables future computational studies of far-from-equilibrium phenomena.

Abstract

We consider the theoretical model of Bergmann and Lebowitz for open systems out of equilibrium and translate its principles in the adaptive resolution molecular dynamics technique (AdResS). We simulate Lennard-Jones fluids with open boundaries in a thermal gradient and find excellent agreement of the stationary responses with results obtained from the simulation of a larger, locally forced closed system. The encouraging results pave the way for a computational treatment of open systems far from equilibrium framed in a well-established theoretical model that avoids possible numerical artifacts and physical misinterpretations.