Voronoi topology improves crystal structure identification in simulations
Structural identification in general crystalline systems via Voronoi cell topology
Computational Geometry
Summary
Identifying different types of crystal structures in computer simulations is usually limited to a few simple patterns. The authors developed a method that looks at the shapes around each atom called Voronoi cells, including small changes that happen at higher temperatures. This method can classify a wide variety of crystal structures automatically, even complex ones. They tested their method on several common crystalline materials and showed it works well.
What this means in practice
- •For materials engineers: Automatically classify complex crystal structures in simulation data to improve materials design processes.
- •For computational chemists: Analyze atomic arrangements in simulations more accurately by identifying the topology of atomic environments under thermal fluctuations.
Authors
Emanuel A. Lazar, Chris H. Rycroft
Abstract
Widely used methods for identifying crystal structure in atomistic simulations are limited in practice to a handful of simple structures, leaving many important crystalline systems without automated classification techniques. Voronoi topology analysis offers a route to classifying arbitrary crystalline and defect environments, but realizing this potential first requires enumerating the Voronoi cell topologies that can arise under thermal perturbation of a structure of interest. We present an algorithm that deterministically enumerates all Voronoi cell topologies arising from generic infinitesimal perturbations of an arbitrary crystal structure, producing structural classifiers that extend automated identification to general crystalline systems. We demonstrate the approach on several structures of general interest.