Determination of the friction coefficient via the force autocorrelation function. A molecular dynamics investigation for a dense Lennard-Jones fluid

Journal Article · Wed Apr 01 04:00:00 EST 1987 · J. Stat. Phys.; (United States)

DOI:https://doi.org/10.1007/BF01009042· OSTI ID:6322665

Vogelsang, R; Hoheisel, C

For a large region of dense fluid states of a Lennard-Jones system, they have calculated the friction coefficient by the force autocorrelation function of a Brownian-type particle by molecular dynamics (MD). The time integral over the force autocorrelation function showed an interesting behavior and the expected plateau value when the mass of the Brownian particle was chosen to be about a factor of 100 larger than the mass of the fluid particle. Sufficient agreement was found for the friction coefficient calculated by this way and that obtained by calculations of the self-diffusion coefficient using the common relation between these coefficients. Furthermore, a modified friction coefficient was determined by integration of the force autocorrelation function up to the first maximum. This coefficient can successfully be used to derive a reasonable soft part of the friction coefficient necessary for the Rice-Allnatt approximation for the shear velocity and simple liquids.

• Research Organization: Ruhruniversitaet Bochum, West Germany
• OSTI ID: 6322665
• Journal Information: J. Stat. Phys.; (United States), Journal Name: J. Stat. Phys.; (United States) Vol. 47:1-2; ISSN JSTPB
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BOLTZMANN STATISTICS
BROWNIAN MOVEMENT
CHAPMAN-ENSKOG THEORY
CORRELATION FUNCTIONS
DIFFUSION
EQUATIONS
FLUIDS
FRICTION FACTOR
FUNCTIONS
GASES
HARD-SPHERE MODEL
INTEGRAL TRANSFORMATIONS
INTERATOMIC FORCES
LANGEVIN EQUATION
LAPLACE TRANSFORMATION
LENNARD-JONES POTENTIAL
LIQUIDS
MATHEMATICAL MODELS
MECHANICS
MOLECULES
PARTICLE MODELS
POTENTIALS
SELF-DIFFUSION
SHEAR
STATISTICAL MECHANICS
THERMODYNAMICS
TIME DEPENDENCE
TRANSFORMATIONS
VISCOSITY