# Configurational entropy measurements in extremely supercooled liquids that break the glass ceiling

## TL;DR

This study uses advanced computational methods to measure configurational entropy in supercooled liquids, confirming the entropy crisis hypothesis and bridging the gap between experimental and simulation timescales.

## Contribution

It introduces novel in-silico configurations and applies multiple entropy estimation techniques to validate the entropy crisis in supercooled liquids beyond experimental limits.

## Key findings

- Consistent entropy decrease observed in simulations and experiments.
- Extended the observational window into glass physics.
- Reinforced the role of entropy crisis in glass formation.

## Abstract

Liquids relax extremely slowly upon approaching the glass state. One explanation is that an entropy crisis, due to the rarefaction of available states, makes it increasingly arduous to reach equilibrium in that regime. Validating this scenario is challenging, because experiments offer limited resolution, while numerical studies lag more than eight orders of magnitude behind experimentally-relevant timescales. In this work we not only close the colossal gap between experiments and simulations but manage to create in-silico configurations that have no experimental analog yet. Deploying a range of computational tools, we obtain four estimates of their configurational entropy. These measurements consistently confirm that the steep entropy decrease observed in experiments is also found in simulations, even beyond the experimental glass transition. Our numerical results thus extend the new observational window into the physics of glasses and reinforce the relevance of an entropy crisis for understanding their formation.