qeirreps

Official Resources

• Homepage: https://github.com/mizoguche/qeirreps
• GitHub: https://github.com/mizoguche/qeirreps
• Publication: A. Matsugatani et al., Comput. Phys. Commun. 264, 107948 (2021)
• License: MIT License

Overview

qeirreps is an open-source program that computes irreducible representations of Bloch wavefunctions from Quantum ESPRESSO output. It analyzes the symmetry character of electronic bands at high-symmetry k-points, enabling topological classification and symmetry-based materials analysis.

Scientific domain: Electronic structure symmetry, irreducible representations, topological materials Target user community: Quantum ESPRESSO users studying band topology and symmetry properties

Theoretical Methods

• Bloch wavefunction symmetry analysis
• Irreducible representation assignment
• Non-symmorphic space group handling
• Spinor representations (spin-orbit coupling)
• Symmetry eigenvalue computation

Capabilities (CRITICAL)

• QE Integration: Direct interface with Quantum ESPRESSO
• Irrep Assignment: Automatic band symmetry classification
• Spin-Orbit: Handles SOC calculations
• Non-symmorphic: Proper phase factors for glide/screw
• Topological Analysis: Symmetry indicator extraction
• Multiple k-points: Batch processing capability

Sources: qeirreps documentation, CPC publication

Key Strengths

Quantum ESPRESSO Native:

• Direct QE output parsing
• Consistent with QE conventions
• Handles QE-specific formats
• No intermediate conversion

Topological Materials:

• Symmetry indicator computation
• Band topology diagnosis
• Compatibility with TQC database
• Fragile topology detection

Robust Implementation:

• Validated against known materials
• Handles complex structures
• Proper SOC treatment
• Non-symmorphic accuracy

Inputs & Outputs

• Input formats:

  • Quantum ESPRESSO output files
  • Wavefunction files (wfc*.dat)
  • Band structure output

• Output data types:

  • Irreducible representation labels
  • Symmetry eigenvalues
  • Character tables
  • Topological indicators

Installation

git clone https://github.com/mizoguche/qeirreps.git
cd qeirreps
make

Usage Examples

# Run after QE band calculation
qeirreps.x -pp < input.nml

# Input namelist
&inputpp
  prefix = 'silicon'
  outdir = './tmp/'
  filband = 'bands.dat'
/

Performance Characteristics

• Speed: Fast symmetry analysis
• Memory: Moderate for wavefunction handling
• Scalability: Handles multiple bands efficiently

Limitations & Known Constraints

• QE-specific: Only works with Quantum ESPRESSO
• k-point selection: Requires high-symmetry points
• Wavefunction access: Needs QE wavefunction files

Comparison with Other Tools

• vs irvsp: qeirreps for QE, irvsp for VASP
• vs IrRep: Both compute irreps, different DFT interfaces
• vs spgrep: qeirreps DFT-specific, spgrep general
• Unique strength: Native Quantum ESPRESSO integration

Application Areas

• Topological insulator identification
• Symmetry-protected topology
• Band inversion analysis
• Weyl/Dirac semimetal classification
• Elementary band representation decomposition

Best Practices

• Use consistent symmetry settings in QE
• Include enough bands for analysis
• Verify k-point high-symmetry assignment
• Check against known materials

Community and Support

• GitHub repository
• CPC publication methodology
• Academic development (Watanabe group)

Verification & Sources

Primary sources:

1. GitHub: https://github.com/mizoguche/qeirreps
2. A. Matsugatani et al., Comput. Phys. Commun. 264, 107948 (2021)

Confidence: VERIFIED - Published in CPC

Verification status: ✅ VERIFIED

• Official repository: ACCESSIBLE
• Documentation: AVAILABLE
• Source code: OPEN (GitHub, MIT)
• Academic citations: CPC publication
• Active development: Maintained