# Suppression of crystalline fluctuations by competing structures in a supercooled liquid

## TL;DR

This paper introduces a geometric measure called crystal affinity to predict how local structures in supercooled liquids influence crystallization, linking structural covariance to nucleation rates and glass-forming ability.

## Contribution

It proposes the crystal affinity as a new quantitative measure to predict crystallization suppression or promotion in supercooled liquids based on local structural covariances.

## Key findings

- Crystal affinity correlates with nucleation rate.
- Anticorrelation with crystalline order reduces crystallization tendency.
- Predicts glass-forming ability based on local structure.

## Abstract

We propose a geometrical characterization of amorphous liquid structures that suppress crystallization by competing locally with crystalline order. We introduce for this purpose the crystal affinity of a liquid, a simple measure of its propensity to accumulate local crystalline structures on cooling. This quantity is explicitly related to the high temperature structural covariance between local fluctuations in crystal order and that of competing liquid structures: favouring a structure that, due to poor overlap properties, anticorrelates with crystalline order reduces the affinity of the liquid. Using a lattice model of a liquid, we show that this quantity successfully predicts the tendency of a liquid to either accumulate or suppress local crystalline fluctuations with increasing supercooling. We demonstrate that the crystal affinity correlates strongly with the crystal nucleation rate and the crystal-liquid interfacial free energy of the low-temperature liquid, making our theory a predictive tool to determine easily which amorphous structures enhance glass-forming ability.