In the evaluation of material properties, the structural configuration of atoms constituting the material is of importance. Presented in this paper is a mathematical and computational methodology to efficiently classify a given atomic structure of an arbitrary material into groups of atoms defining BCC, FCC, and HCP crystal structures. The approach is based on the angular distributions among neighboring atoms efficiently identified by a computational geometry technique called a Voronoi diagram. Usually a Voronoi diagram consists of Voronoi regions for each atom where a Voronoi region consists of points in space which is closer to an associated atom than the others. Due to the computational efficiency of a Voronoi diagram, the proposed approach becomes more powerful as the number of atoms is increased.

Keywords: Crystal Structure, Voronoi Diagram, Geometric Algorithm, Angle distribution