Transport and Helfand moments in the Lennard-Jones fluid. I. Shear viscosity

Viscardy S., Servantie J., GASPARD P.

JOURNAL OF CHEMICAL PHYSICS, vol.126, no.18, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 126 Issue: 18
  • Publication Date: 2007
  • Doi Number: 10.1063/1.2724820
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Istanbul Technical University Affiliated: No


The authors propose a new method, the Helfand-moment method, to compute the shear viscosity by equilibrium molecular dynamics in periodic systems. In this method, the shear viscosity is written as an Einstein-type relation in terms of the variance of the so-called Helfand moment. This quantity is modified in order to satisfy systems with periodic boundary conditions usually considered in molecular dynamics. They calculate the shear viscosity in the Lennard-Jones fluid near the triple point thanks to this new technique. They show that the results of the Helfand-moment method are in excellent agreement with the results of the standard Green-Kubo method. (C) 2007 American Institute of Physics.