Controlling crystallization: what liquid structure and dynamics reveal about crystal nucleation mechanisms

Over recent years, molecular simulations have provided invaluable insights into the microscopic processes governing the initial stages of crystal nucleation and growth. A key aspect that has been observed in many different systems is the formation of precursors in the supercooled liquid that precedes the emergence of crystalline nuclei. The structural and dynamical properties of these precursors determine to a large extent the nucleation probability as well as the formation of specific polymorphs. This novel microscopic view on nucleation mechanisms has further implications for our understanding of the nucleating ability and polymorph selectivity of nucleating agents, as these appear to be strongly linked to their ability in modifying structural and dynamical characteristics of the supercooled liquid, namely liquid heterogeneity. In this perspective, we highlight recent progress in exploring the connection between liquid heterogeneity and crystallization, including the effects of templates, and the potential impact for controlling crystallization processes.This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.

Automated summary

In recent years, molecular simulations have provided valuable insights into the microscopic processes of crystal nucleation and growth. Precursors formed in the supercooled liquid before crystalline nuclei emerge are observed in many systems, and their structural and dynamical properties significantly influence nucleation probability and polymorph formation. This novel understanding of nucleation mechanisms has implications for the nucleating ability and polymorph selectivity of nucleating agents, which are strongly linked to their impact on the structural and dynamical characteristics of the supercooled liquid, known as liquid heterogeneity. This perspective highlights recent progress in exploring the connection between liquid heterogeneity and crystallization, including the effects of templates and the potential for controlling crystallization processes.