Scaling of Volumetric Data in Model Systems Based on the Lennard-Jones Potential

TL;DR

This paper demonstrates that volumetric data from Lennard-Jones based molecular models can be scaled using the same exponent as dynamic data, linking thermodynamics and molecular dynamics in viscous systems.

Contribution

It shows that volumetric data scaling aligns with dynamic data scaling in Lennard-Jones models, resolving previous inconsistencies.

Findings

Volumetric data from LJ models can be scaled with the same exponent as dynamic data.

The scaling exponent relates to the inverse power law of the LJ potential.

Results unify thermodynamic and dynamic scaling in viscous liquids.

Abstract

The crucial problem for better understanding the nature of glass transition and related relaxation phenomena is to find proper interrelations between molecular dynamics and thermodynamics of viscous systems. To gain this aim the recently observed density scaling of viscous liquid dynamics has been very intensively and successfully studied for last years. However, previous attempts at related scaling of volumetric data yielded results inconsistent with those found from the density scaling of molecular dynamics. In this Letter, we show that volumetric data obtained from simulations in simple molecular models based on the Lennard-Jones (LJ) potential, such as Kob-Andersen binary liquids and the Lewis-Wahnstr\"om o-terphenyl model, can be scaled by using the same value of the exponent, which scales dynamic quantities and is directly related to the exponent of the repulsive inverse power law that underlies short-range approximations of the LJ potential.