Structural (dis)order and dynamic propensity in a mildly undercooled glass-forming liquid: Spatial correlations and the role of crystalline environments

TL;DR

This study investigates how local structural order and crystalline environments influence dynamic heterogeneities in a mildly undercooled glass-forming liquid, revealing strong correlations and the role of crystalline regions in slow dynamics.

Contribution

It demonstrates the connection between tetrahedral order heterogeneities and dynamic propensity, highlighting the influence of crystalline environments on slow dynamics in undercooled liquids.

Findings

Spatially correlated tetrahedral clusters are observable during structural relaxation.

Angular tetrahedral order strongly correlates with dynamics.

Crystalline environments may cause slow dynamics in undercooled water.

Abstract

We use the isoconfigurational (IC) ensemble to show the connection between emerging heterogeneities in the tetrahedral order parameter and the dynamic propensity in a mildly undercooled glass-forming liquid. We observe that spatially correlated tetrahedrally-(dis)ordered clusters of molecules are observable on the time scale of structural relaxation. The heterogeneities of tetrahedrally-(dis)ordered clusters correlate with dynamical heterogeneities (DH) and these correlations reach peaks at similar time scales. We discover that the angular component of the tetrahedral order parameter is strongly correlated to the dynamics compared to the radial component. Moreover, these correlations between the dynamics and tetrahedrally-(dis)ordered regions enormously influence the system, with spatial correlations being observable for a prolonged period beyond the peaks of maximum DH. Further, we discover that the crystalline particle environments in our water model (as identified by the IC ensemble) may be the origin for slow dynamics of dynamical heterogeneity in our undercooled model water system.