pytopomat

Official Resources

• Homepage: https://github.com/ncfrey/pytopomat
• Repository: https://github.com/ncfrey/pytopomat
• License: MIT License

Overview

pytopomat is a Python package designed for the high-throughput screening of topological materials within the Materials Project ecosystem. It provides a user-friendly interface to apply the theory of Topological Quantum Chemistry (TQC) to crystal structures, allowing users to automatically diagnose whether a material is topological or trivial based on its symmetry and valence electron count, often without expensive surface state calculations.

Scientific domain: Materials Informatics, High-Throughput Topology Target user community: Data Scientists, Materials Project users

Theoretical Methods

• Topological Quantum Chemistry (TQC): Mapping rules between atomic limits and band representations.
• Symmetry Indicators: Detection of topological bands via symmetry eigenvalues.
• Fu-Kane Parity: $\mathbb{Z}_2$ classification for centrosymmetric crystals.
• Spillage Criteria: Quantifying the change in wavefunction character due to Spin-Orbit Coupling.

Capabilities

• Screening:
  • is_topological(structure): Boolean check for topological bands.
  • get_symmetries(): Extracts relevant space group info.
• Database Integration:
  • Fetches pre-computed topology data from the Materials Project API.
  • Integration with atomate workflows for VASP.
• Symmetry Analysis:
  • Verification of Wyckoff positions and stoichiometry against TQC rules.

Key Strengths

• Informatics Ready: Built on top of pymatgen, making it the easiest tool for users already comfortable with the Materials Project Python stack.
• Scale: Optimized for screening thousands of compounds, rather than deep-diving into one.
• Simplicity: Abstracts the heavy group theory of TQC into simple function calls.

Inputs & Outputs

• Inputs: pymatgen.Structure objects.
• Outputs: Boolean flags, symmetry indicator lists.

Interfaces & Ecosystem

• Dependencies: pymatgen, spglib, numpy.
• Integration: Materials Project REST API.

Performance Characteristics

• Speed: Instantaneous for lookups or symmetry checks.
• Bottleneck: Depends on backend DFT if running new calculations.

Comparison with Other Codes

• vs. TopMat: TopMat handles Magnetic Space Groups (1651). pytopomat focuses on the standard Space Groups (230) and non-magnetic materials.
• vs. IrRep: IrRep is the low-level calculator of traces. pytopomat is the high-level screening logic.

Application Areas

• Mining Databases: Finding new candidate Topological Insulators in ICSD.
• Dataset Creation: Generating labels for machine learning models of topology.

Community and Support

• Development: Nathan C. Frey (UPenn / Berkeley).
• Source: GitHub.

Verification & Sources

• Repository: https://github.com/ncfrey/pytopomat
• Verification status: ✅ VERIFIED
  • Valid informatics tool.