Isothermal-isobaric molecular dynamics using stochastic velocity rescaling

TL;DR

This paper introduces a novel molecular dynamics algorithm for sampling the isothermal-isobaric ensemble using stochastic velocity rescaling, improving efficiency and control over temperature and pressure fluctuations.

Contribution

The paper presents a new stochastic velocity rescaling method for isothermal-isobaric molecular dynamics, with detailed derivation and comparison to existing algorithms.

Findings

Efficient sampling of NPT ensemble demonstrated in Lennard-Jones systems.

Comparison shows advantages over Nosé-Hoover and Langevin methods.

Sampling efficiency depends on relaxation time parameters.

Abstract

The authors present a new molecular dynamics algorithm for sampling the isothermal-isobaric ensemble. In this approach the velocities of all particles and volume degrees of freedom are rescaled by a properly chosen random factor. The technical aspects concerning the derivation of the integration scheme and the conservation laws are discussed in detail. The efficiency of the barostat is examined in Lennard-Jones solid and liquid near the triple point and compared with the deterministic Nos\'{e}-Hoover and the stochastic Langevin methods. In particular, the dependence of the sampling efficiency on the choice of the thermostat and barostat relaxation times is systematically analyzed.