WulffPack – A Python Package for Wulff Constructions

Magnus Rahm and Paul Erhart
Chalmers University of Technology, Sweden

The Wulff construction provides the minimum energy shape for a given set of facet-dependent surface energies. It is a valuable tool for example in nanoscience, as it provides an estimate of the equilibrium shape of nanoparticles. WulffPack [1] is an open-source Python package that uses ASE and various other tools to make Wulff constructions for any crystal symmetry. The resulting Wulff shapes can be obtained either as ASE Atoms objects or as continuum models in raw coordinates. It makes regular single crystalline Wulff constructions as well as constructions of particles with decahedral and icosahedral symmetry, and it allows for Wulff constructions on flat surfaces, so-called Winterbottom constructions. The results are easily visualized with Matplotlib. For even simpler access, a web application which interactively creates Wulff constructions has also been developed [2].