Imperial College London

Professor Erich A. Muller

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Thermodynamics



+44 (0)20 7594 1569e.muller Website




Miss Raluca Leonte +44 (0)20 7594 5557




409ACE ExtensionSouth Kensington Campus






BibTex format

author = {Jaeger, F and Matar, OK and Muller, EA},
doi = {10.1063/1.5022752},
journal = {Journal of Chemical Physics},
title = {Bulk viscosity of molecular fluids},
url = {},
volume = {148},
year = {2018}

RIS format (EndNote, RefMan)

AB - The bulk viscosity of molecular models of gases and liquids is determined by molecular simulations as acombination of a dilute gas contribution, arising due to the relaxation of internal degrees of freedom, and aconfigurational contribution, due to the presence of intermolecular interactions. The dilute gas contributionis evaluated using experimental data for the relaxation times of vibrational and rotational degrees of freedom.The configurational part is calculated using Green-Kubo relations for the fluctuations of the pressure tensorobtained from equilibrium microcanonical molecular dynamics simulations. As a benchmark, the Lennard-Jones fluid is studied. Both atomistic and coarse-grained force fields for water, CO2and n-decane areconsidered and tested for their accuracy. Comparison to experimental data, where present, demonstratesthat the tested models show various degrees of success in predicting bulk viscosity values, although atomisticforce fields in general seem to perform more consistently than the corresponding coarse-grained counterparts.The dilute gas contribution to the bulk viscosity is seen to be significant only in the cases when intramolecularrelaxation times are in theμs range, and for low vibrational wave numbers (<1000 cm−1); This explainsthe abnormally high values of bulk viscosity reported for CO2. In all other cases studied, the dilute gascontribution is negligible, and the configurational contribution dominates the overall behaviour. In particular,the configurational term is responsible for the enhancement of the bulk viscosity near the critical point.
AU - Jaeger,F
AU - Matar,OK
AU - Muller,EA
DO - 10.1063/1.5022752
PY - 2018///
SN - 0021-9606
TI - Bulk viscosity of molecular fluids
T2 - Journal of Chemical Physics
UR -
UR -
VL - 148
ER -