qeirreps: an open-source program for Quantum ESPRESSO to compute irreducible representations of Bloch wavefunctions

TL;DR

qeirreps is an open-source tool that analyzes Quantum ESPRESSO outputs to determine symmetry representations of Bloch wavefunctions and identify potential topological materials using symmetry indicators.

Contribution

The paper introduces qeirreps, a new open-source program that computes irreducible representations and topological indices from Quantum ESPRESSO data, facilitating topological material discovery.

Findings

qeirreps accurately computes symmetry representations from Quantum ESPRESSO outputs.

The program calculates the Z4 index for inversion-symmetric materials.

qeirreps enables exploration of topological properties in materials.

Abstract

Bloch wavefunctions in solids form a representation of crystalline symmetries. Recent studies revealed that symmetry representations in band structure can be used to diagnose the topological properties of weakly interacting materials. In this work, we introduce an open-source program qeirreps that computes the representation characters in a band structure based on the output file of Quantum ESPRESSO. Our program also calculates the Z4 index, i.e., the sum of inversion parities at all time-reversal invariant momenta, for materials with inversion symmetry. When combined with the symmetry indicator method, this program can be used to explore new topological materials.