Freezing density scaling of transport coefficients in the Weeks-Chandler-Andersen fluid

TL;DR

This paper demonstrates that transport coefficients of the Weeks-Chandler-Andersen fluid follow a freezing density scaling law similar to other simple fluids, indicating a quasi-universal behavior in classical fluids with steep interactions.

Contribution

It reveals a quasi-universal freezing density scaling for transport coefficients in the WCA fluid, extending the concept across different simple classical fluids.

Findings

Transport coefficients follow a similar FDS in WCA, Lennard-Jones, and hard-sphere fluids.

FDS acts as a quasi-universal principle for simple classical fluids.

Proposes simple fitting formulas for dense WCA fluid transport properties.

Abstract

It is shown that the transport coefficients (self-diffusion, shear viscosity, and thermal conductivity) of the Weeks-Chandler-Anderson (WCA) fluid along isotherms exhibit a freezing density scaling (FDS). The functional form of this FDS is essentially the same or closely related to those in the Lennard-Jones fluid, hard-sphere fluid, and some liquefied noble gases. This proves that this FDS represents a quasi-universal corresponding state principle for simple classical fluids with steep interactions. Some related aspects such as Stokes-Einstein relation without a hydrodynamic diameter and gas-to-liquid dynamical crossover are briefly discussed. Simple fitting formula for the transport coefficients of the dense WCA fluid are suggested.