On the relationship between structure and dynamics in a supercooled liquid

TL;DR

This paper investigates how the initial structure influences the dynamics in a supercooled liquid, revealing that local structural measures do not strongly predict dynamic propensity, highlighting the non-local nature of collective behavior.

Contribution

It introduces the dynamic propensity distribution as a measure and analyzes its correlation with local structural features in a supercooled liquid.

Findings

High propensity associated with small particles

No strong correlation between local structure and propensity

Highlights non-local character of collective dynamics

Abstract

We present the dynamic propensity distribution as an explicit measure of the degree to which the dynamics in a liquid over the time scale of structural relaxation is determined by the initial configuration. We then examine, for a binary mixture of soft discs in two dimensions, the correlation between the spatial distribution of propensity and that of two localmeasures of configuration structure: the local composition and local free volume. While the small particles dominate the high propensity population,we find no strong correlation between either the local composition or the local free volume and the propensity. It is argued that this is a generic failure of purely local structural measures to capture the inherently non-local character of collective behaviour.