Dionisios Margetis University of Maryland Mathematics, and Institute for Physical Science & Technology This talk addresses aspects of a classic question in epitaxial growth: May facets of evolving crystal surfaces be described by fully continuum models? A difficulty in the use of traditional, PDE-based approaches for this problem lies in the development of (time-dependent) singularities of continuum solutions in the vicinity of the facet; such singularities may indicate the breakdown of the continuum theory. By invoking an evaporation model for line defects (steps) of crystal surfaces, I discuss the connection of a fully continuum variational approach for facets to the underlying microstructure. This is joint work with Kanna Nakamura.