Anatomy of a Complex Crystallization Pathway

TL;DR

This study uses molecular dynamics to compare crystallization pathways of two systems with different interactions, revealing similar polymorphs and pathways due to effective interaction similarities.

Contribution

It demonstrates that different particle interactions can lead to similar crystallization pathways and structures when mapped to effective pairwise potentials.

Findings

Both systems are polymorphic and share the same crystal structures.

They follow similar multistep crystallization pathways.

Local structural evolution is comparable between systems.

Abstract

Using molecular dynamics simulations, we investigate the crystallization pathways of two exemplary systems that form the same complex crystal structure but differ fundamentally in the nature of their particle interactions. One system is composed of point particles interacting via an isotropic pair potential characteristic of metallic compounds, while the other system contains hard polyhedra whose interactions arise from emergent entropic forces. Despite the stark difference in the origins of the particle interactions, we find that both systems are polymorphic and share the same crystal polymorphs. Moreover, the two systems follow the same multistep crystallization pathways, and by examining the complex crystallization pathways on the single particle level, we find that the local structure evolution of the two systems is also similar. By mapping the hard particle system's interaction to an effective pairwise potential, we find that such resemblance arises from the particle interactions being effectively similar.