One of the central challenges in multiscale modeling,
consists of how to bridge the gap among atomistic and macroscopic approaches in
order to ensure that the descriptions at all levels are quantitatively consistent with
each other. In our work, we carry out this task for the hierarchical coupling approach that
combines molecular dynamics (MD) with phase-field (PF) modeling. The consistency
analysis is achieved by detailed comparisons of quantitative predictions of the
considered modeling methods for the kinetics of crystal growth from the melt. The latter is
a typical multiscale problem in materials physics. The MD simulations provide the physical
quantities needed for the construction of the multiscale model. Of central importance
are the free-energy values of the bulk liquid and of the solid-liquid interface.
In particular, we link MD to PF modeling in order to estimate quantitatively the
influence of the solid-liquid interface confinement (reduced diffusion in liquid) and
of the ’in-plane’ solid-liquid interface ordering on the growth kinetics. These issues will be
illustrated for the binary alloy NiZr and monatomic system Fe. Our observations provide
evidence for a strong link between the interface ordering and the short-range order in the
bulk liquid. These findings are of relevance for the alloy-growth kinetics as well as for the
fundamental issue of local (atomic) structure of metallic liquids.
 M. Guerdane, H. Teichler, and B. Nestler, PRL 110, 086105 (2013).