Dynamics of the Gay-Berne fluid
- Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Apartado 1065, Sevilla 41080 (Spain)
- School of Chemical Engineering, Cornell University, Ithaca, New York 14853 (United States)
Using molecular-dynamics computer simulation, we study the dynamical behavior of the isotropic and nematic phases of highly anisotropic molecular fluids. The interactions are modeled by means of the Gay-Berne potential with anisotropy parameters {kappa}=3 and {kappa}{prime}=5. The linear-velocity autocorrelation function shows no evidence of a negative region in the isotropic phase, even at the higher densities considered. The self-diffusion coefficient parallel to the molecular axis shows an anomalous increase with density as the system enters the nematic region. This enhancement in parallel diffusion is also observed in the isotropic side of the transition as a precursor effect. The molecular reorientation is discussed in the light of different theoretical models. The Debye diffusion model appears to explain the reorientational mechanism in the nematic phase. None of the models gives a satisfactory account of the reorientation process in the isotropic phase.
- OSTI ID:
- 7047459
- Journal Information:
- Physical Review A. General Physics; (United States), Journal Name: Physical Review A. General Physics; (United States) Vol. 45:6; ISSN PLRAA; ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERIZED SIMULATION
CORRELATION FUNCTIONS
COUPLING
DIFFUSION
DYNAMICS
FLUID MECHANICS
FUNCTIONS
ISOTROPY
MECHANICS
MOLECULES
MOTION
POTENTIALS
ROTATION
SELF-DIFFUSION
SIMULATION
TIME DEPENDENCE
VELOCITY