Velocity autocorrelation function of a Brownian particle

Abstract

In this article, we present molecular dynamics study of the velocity autocorrelation function (VACF) of a Brownian particle. We compare the results of the simulation with the exact analytic predictions for a compressible fluid from [6] and an approximate result combining the predictions from hydrodynamics at short and long times. The physical quantities which determine the decay were determined from separate bulk simulations of the Lennard-Jones fluid at the same thermodynamic state point.We observe that the long-time regime of the VACF compares well the predictions from the macroscopic hydrodynamics, but the intermediate decay is sensitive to the viscoelastic nature of the solvent.

7 pages, 6 figures

References in corpus (3)

• Hydrodynamic interactions and Brownian forces in colloidal suspensions: Coarse-graining over time and length-scales
• Highly accelerated simulations of glassy dynamics using GPUs: caveats on limited floating-point precision
• Velocity autocorrelation function of a Brownian particle

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• Diffusion of a Janus nanoparticle in an explicit solvent: A molecular dynamics simulation study
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• Molecular hydrodynamic theory of the velocity autocorrelation function
• Continuous demixing transition of binary liquids: finite-size scaling from the analysis of sub-systems
• Modeling Brownian Motion as a Timelapse of the Physical, Persistent, Trajectory