Homogeneous nucleation of a crystalline phase from moderately undercooled liquid is a typical rare event and is inaccessible within the limited timescales of conventional molecular dynamics (MD) simulations. In this talk, we present a “persistent embryo” method to facilitate crystal nucleation in MD simulations, in which a small crystal embryo is inserted into the liquid, with spring forces applied to keep the embryo from melting. The springs are gradually weakened as the embryo grows and are completed removed when the nucleus size remains significantly smaller than the critical size.  In this way, one can observe the spontaneous fluctuations of a critical nucleus in an unbiased environment, without any assumptions on the shape of the critical nucleus. We applied this method to simulate crystal nucleation in both metallic and hard-sphere systems under realistic experimental conditions, and obtained results that compare favorably with experiments and other simulation methods. We strongly believe that this method will see a wide range of applications in molecular and supramolecular systems as well. <br/>

Overcoming the time limitation in molecular dynamics simulation of crystal nucleation: A persistent-embryo approach

2019 Spring National Meeting

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