BCN-M: A Free Computational Tool for Generating Wulff-like Nanoparticle Models with Controlled Stoichiometry

A thorough knowledge of the atomic structure of nanomaterials is of high importance to understand their properties. This requires developing nanoparticle models, which is not always straightforward, particularly in the case of nonpure metallic systems. The bulk cut nanoparticle model (BCN-M) computational tool generates Wulff-like models for binary materials with controlled stoichiometry automatically with none or little need for further manipulation from the user. The models are obtained exclusively by introducing the structure of the bulk material, its symmetry, the surface energies of the most representative surfaces, and information about surface termination as input data. The algorithm produces different structural model sets, and the quality of these models is evaluated using different criteria: (i) the deviation from an ideal Wulff shape, (ii) the global coordination of surface metal atoms, and (iii) the polarity of the model. BCN-M has been applied to 15 different materials, leading to a variety of models that cover the most relevant binary ionic structures and symmetries (cubic, tetragonal, hexagonal, and monoclinic). The resulting models can be used for structure analysis of ideal systems as well as their simulation. BCN-M is available as a free web platform (https://bcnm.qf.uab.cat) or as a downloadable utility, and it is expected to be an important tool for the design of future nanomaterials.