Molecular hydrodynamics from memory kernels

Dominika Lesnicki; Rodolphe Vuilleumier; Antoine Carof; Benjamin Rotenberg

doi:10.1103/physrevlett.116.147804

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arXiv · 1605.03075

Molecular hydrodynamics from memory kernels

Dominika Lesnicki·Rodolphe Vuilleumier·Antoine Carof·Benjamin Rotenberg

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Abstract

The memory kernel for a tagged particle in a fluid, computed from molecular dynamics simulations, decays algebraically as $t^{-3/2}$. We show how the hydrodynamic Basset-Boussinesq force naturally emerges from this long-time tail and generalize the concept of hydrodynamic added mass. This mass term is negative in the present case of a molecular solute, at odds with incompressible hydrodynamics predictions. We finally discuss the various contributions to the friction, the associated time scales and the cross-over between the molecular and hydrodynamic regimes upon increasing the solute radius.

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Dominika Lesnicki, Rodolphe Vuilleumier, Antoine Carof, Benjamin Rotenberg. 2016-05-10. Molecular hydrodynamics from memory kernels. https://doi.org/10.1103/physrevlett.116.147804

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