DiSPy: Implementation of Distortion Symmetry for the Nudged Elastic Band Method

TL;DR

This paper introduces DiSPy, a software tool that utilizes distortion symmetry to systematically explore multiple pathways in the nudged elastic band method, improving the accuracy and diversity of minimum energy pathway calculations.

Contribution

The paper presents a novel implementation of symmetry-adapted perturbations in NEB using group theory, enabling systematic exploration of low-energy pathways.

Findings

Enhanced ability to find multiple minimum energy pathways.

Discovery of new pathways with higher atomic coordination.

Simplified process for obtaining previously reported pathways.

Abstract

The nudged elastic band (NEB) method is a commonly used approach for the calculation of minimum energy pathways of kinetic processes. However, the final paths obtained rely heavily on the nature of the initially chosen path. This often necessitates running multiple calculations with differing starting points in order to obtain accurate results. Recently, it has been shown that the NEB algorithm can only conserve or raise the distortion symmetry exhibited by an initial pathway. Using this knowledge, symmetry-adapted perturbations can be generated and used as a tool to systematically lower the initial path symmetry, enabling the exploration of other low-energy pathways that may exist. The group and representation theory details behind this process are presented and implemented in a standalone piece of software (DiSPy). The method is then demonstrated by applying it to the calculation of ferroelectric switching pathways in LiNbO3. Previously reported pathways are more easily obtained, with new paths also being found which involve a higher degree of atomic coordination.