Density-scaling exponents and virial potential-energy correlation coefficients for the (2n, n) Lennard-Jones system

Ida Marie Friisberg, Lorenzo Costigliola, Jeppe Dyre

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

This paper investigates the relation between the density-scaling exponent γ and the virial potentialenergy coefficient R at several thermodynamic state points in three dimensions for the generalized (2n, n) Lennard-Jones (LJ) system for n = 4, 9, 12, 18, as well as for the standard n = 6 LJ system in two, three, and four dimensions. The state points studied include many low-density states at which the virial potentialenergy correlations are not strong. For these state points we find the roughly linear relation γ ∼= 3n R/d in d dimensions. This result is discussed in light of the approximate “extended inverse power law” description of generalized LJ potentials (Bailey N P et al. 2008 J. Chem. Phys. 129 184508). In the plot of γ versus R there is in all cases a transition around R ≈ 0.9, above which γ starts to decrease as R approaches unity. This is consistent with the fact that γ → 2n/d for R → 1, a limit that is approached at high densities and/or high
temperatures at which the repulsive r−2n term dominates the physics.
OriginalsprogEngelsk
TidsskriftJournal of Chemical Sciences
Vol/bind129
Udgave nummer7
Sider (fra-til)919-928
Antal sider11
ISSN0370-0089
DOI
StatusUdgivet - 2017

Bibliografisk note

Important note from the Publisher regarding the linked version of the article (arXiv). “This is a post-peer-review, pre-copyedit version of an article published in Journal of Chemical Sciences. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12039-017-1307-1”

Emneord

  • Lennard-Jones type liquids
  • isomorphs
  • density scaling
  • virial potential-energy correlations

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