Excess entropy determines the applicability of Stokes-Einstein relation in simple fluids

  title={Excess entropy determines the applicability of Stokes-Einstein relation in simple fluids},
  author={Sergey A. Khrapak and Alexey G. Khrapak},
The Stokes-Einstein (SE) relation between the self-diffusion and shear viscosity coefficients operates in sufficiently dense liquids not too far from the liquid-solid phase transition. By considering four simple model systems with very different pairwise interaction potentials (Lennard-Jones, Coulomb, Debye-Hückel or screened Coulomb, and the hard sphere limit) we identify where exactly on the respective phase diagrams the SE relation holds. It appears that the reduced excess entropy sex can be… 

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  • Hodgdon, Stillinger
  • Physics, Medicine
    Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
  • 1993
It is proposed that special thermal fluctuations cause domains in the liquid to become temporarily more Auidized, so that a diffusing particle can move through fluidized regions, but is inhibited from moving in the unAuidized region.