Landscape equivalent of the shoving model

TL;DR

This paper demonstrates that the shoving model's relaxation time expression can be derived from a classical energy landscape perspective, linking the models through barrier height estimations involving elastic moduli.

Contribution

It shows that the shoving model's relaxation time formula can be derived from landscape estimations, highlighting the role of elastic moduli in viscous liquids.

Findings

The landscape estimation aligns with the shoving model's predictions.

Bulk modulus contributes less than 8% to activation energy's temperature dependence.

The physics of the landscape and shoving models are closely related.

Abstract

It is shown that the shoving model expression for the average relaxation time of viscous liquids follows largely from a classical "landscape" estimation of barrier heights from curvature at energy minima. The activation energy involves both instantaneous bulk and shear moduli, but the bulk modulus contributes less than 8% to the temperature dependence of the activation energy. This reflects the fact that the physics of the two models are closely related.