Molecular Theory of Nucleation from Dilute Phases: Formulation and Application to Lennard-Jones Vapor.

Abstract

In this Letter, we present a molecular theory of nucleation from dilute phases such as vapors or dilute solutions. The theory can model the nonclassical two-step crystal nucleation seen in many systems. When applied to study and analyze the crystal nucleation pathways from Lennard-Jones vapor, we find that prior explanations of the two-step mechanism based on lower barrier height for liquid nuclei is incomplete. The analysis from the molecular theory reveal that a complete explanation would also require consideration of anisotropy in the diffusion constants for growth of liquid droplets vis-á-vis the crystal nuclei.