Three-state structural heterogeneity in a model two dimensional fluid

TL;DR

This study identifies three distinct structural populations in a 2D Lennard-Jones fluid, each with unique properties, which persist across phase transitions, enhancing understanding of dynamical heterogeneity in complex fluids.

Contribution

The paper reveals three stable structural states in a 2D fluid using tessellation analysis, providing new insights into local structure and dynamics.

Findings

Three structural populations with distinct mobility are identified.

Each population maintains its properties across the liquid-solid transition.

Structural heterogeneity correlates with dynamical heterogeneity in the fluid.

Abstract

Three structural populations with distinct average mobility are identified within an equilibrium two-dimensional Lennard-Jones fluid simulated via molecular dynamics at a constant temperature and varying density. Quantifying the structure of the immediate neighborhood of particles by a tessellation allows us to identify three distinct structural states by the shapes of the tessellation cells. Irrespective of dynamic particle exchange among these populations, each is observed to maintain their own thermodynamic and average dynamic properties across the liquid-solid transition. We expect these findings to be valuable for better understanding the structural basis of dynamical heterogeneity in complex fluids defined in terms of local mobility fluctuations.