Stochastic thermostats: comparison of local and global schemes

TL;DR

This paper compares local and global stochastic thermostats, demonstrating that the global scheme better preserves dynamics and enables faster phase-space sampling in molecular simulations.

Contribution

It introduces a global stochastic thermostat as an alternative to the Langevin thermostat and compares their properties both theoretically and through simulations.

Findings

Global thermostat preserves dynamical properties over a wide parameter range.

Global scheme allows for faster phase-space sampling.

Global thermostat is a viable alternative to local Langevin dynamics.

Abstract

We show that a recently introduced stochastic thermostat [J. Chem. Phys. 126 (2007) 014101] can be considered as a global version of the Langevin thermostat. We compare the global scheme and the local one (Langevin) from a formal point of view and through practical calculations on a model Lennard-Jones liquid. At variance with the local scheme, the global thermostat preserves the dynamical properties for a wide range of coupling parameters, and allows for a faster sampling of the phase-space.