AFLOW-SYM: Platform for the complete, automatic and self-consistent symmetry analysis of crystals

TL;DR

AFLOW-SYM provides an automated, self-consistent method for comprehensive symmetry analysis of crystal structures, improving reliability and consistency across large materials databases.

Contribution

It introduces a robust, system-specific tolerance protocol for symmetry determination, validated against extensive crystallographic data, and integrated into the AFLOW framework.

Findings

Validated against 54,000 structures in ICSD

Applied to over 1.7 million entries in AFLOW database

Achieved consistent symmetry classification across diverse structures

Abstract

Determination of the symmetry profile of structures is a persistent challenge in materials science. Results often vary amongst standard packages, hindering autonomous materials development by requiring continuous user attention and educated guesses. Here, we present a robust procedure for evaluating the complete suite of symmetry properties, featuring various representations for the point-, factor-, space groups, site symmetries, and Wyckoff positions. The protocol determines a system-specific mapping tolerance that yields symmetry operations entirely commensurate with fundamental crystallographic principles. The self consistent tolerance characterizes the effective spatial resolution of the reported atomic positions. The approach is compared with the most used programs and is successfully validated against the space group information provided for over 54,000 entries in the Inorganic Crystal Structure Database. Subsequently, a complete symmetry analysis is applied to all 1.7$+$ million entries of the AFLOW data repository. The AFLOW-SYM package has been implemented in, and made available for, public use through the automated, $\textit{ab-initio}$ framework AFLOW.