Geometry guided crystal phase transition pathway search

Recently a periodic surface model was developed to assist geometric construction in computer-aided nano-design. This implicit surface model helps create super-porous nano structures parametrically and supports crystal packing. In this paper, we propose a new approach for pathway search in phase transition simulation of crystal structures. The approach relies on the interpolation of periodic loci surface models. Respective periodic plane models are reconstructed from the positions of individual atoms at the initial and final states, and surface correspondences are found. With geometric constraints imposed based on physical and chemical properties of crystals, two surface interpolation methods are used to approximate the intermediate atom positions on the transition pathway in the full search of the minimum energy path. This hybrid approach integrates geometry information in the configuration space and physics information to allow for an efficient transition pathway search. The methods are demonstrated by examples of FeTi, VO2, and FePt.

► A phase transition pathway design approach is developed for functional materials.
► Geometry and physics information are integrated to improve prediction accuracy.
► Implicit surfaces are reconstructed from periodic crystal structures.
► Geometric constraints based on physical and chemical properties improve efficiency.
► Surface-based interpolation methods provide good initial guesses of transition path.