Molecular Dynamics Investigation of Transient Nucleation in the Freezing of Clusters of SeF6

Abstract

Although theorists have devised a number of different approaches to treat the early (transient) stages of freezing by homogeneous nucleation, no experiments of sufficient accuracy have been performed to check the theories. In the present work a computer experiment is carried out by molecular dynamics simulations in order to make such a check. A system of 2500 independent liquid clusters of SeF6 with an average size of 545 molecules was rapidly cooled to 130 K and maintained at that temperature until each cluster froze. Nucleation times of each cluster were recorded, ordered, and plotted against the quantity − ln[N(t)/No] for comparison with Wu's theory of moments. Results conformed to Wu's expression. From the behavior in the transient region could be derived the reduced moment characterizing the initial, rapidly increasing rate of appearance of nuclei, and from the slope and intercept of the steady state plot could be derived the steady state nucleation rate and nucleation time lag. Although Wu provided ...