A fast and robust crystal symmetry finder, written in Rust.

Each interface has its own README with installation, usage, and development instructions:

• Rust (moyo): core implementation (crates.io, docs)
• Python (moyopy): Python binding (PyPI, docs)
• C (moyoc): C binding, built and consumed with CMake (docs)
• Fortran: Fortran interface on top of the C binding (optional moyo::moyof CMake target)
• JavaScript (moyo-wasm): JavaScript and WebAssembly binding (npm)
• Web viewer: browse the 230 space groups, 80 layer groups, and 1651 magnetic space groups at https://spglib.github.io/moyo/ (static SPA powered by moyo-wasm)

The functionality categories below mirror the sections of the moyopy API reference.

Legend: ✅ supported · 🟡 partial · ❌ not exposed · ➖ not applicable.

Notes:

• Core types are Cell, Operations, and UnimodularTransformation. C exposes Cell, magnetic cells, Operations, and MagneticOperations; WASM exposes only Cell and (implicitly) Operations via the dataset output. UnimodularTransformation is not bound in either.
• "Dataset from cell" is the main symmetry-analysis entry point (MoyoDataset, MoyoLayerDataset, MoyoCollinearMagneticDataset, MoyoNonCollinearMagneticDataset).
• "Data access" covers classification tables and lookup helpers (e.g. Setting, Centering, HallSymbolEntry, SpaceGroupType, ArithmeticCrystalClass, operations_from_number, LayerSetting, LayerCentering, LayerHallSymbolEntry, LayerGroupType, LayerArithmeticCrystalClass, operations_from_layer_number, MagneticSpaceGroupType, magnetic_operations_from_uni_number).
• C's "Data access" is 🟡 because the standalone Centering, ArithmeticCrystalClass, and WyckoffPosition classes are not bound (their content is reachable as strings through the entry and group-type lookups); the settings, Hall symbol entries, group types, and operations_from_* generators are all exposed.
• "Group identification" recovers a group label from a primitive list of symmetry operations (PointGroup + SpaceGroup + integral_normalizer, LayerGroup, MagneticSpaceGroup). C's space-group row is 🟡 because integral_normalizer is not bound; PointGroup, SpaceGroup, LayerGroup, and MagneticSpaceGroup are all exposed.
• The Fortran interface mirrors the C column one-to-one (it wraps the complete moyoc API).

If you use moyo or its interfaces in your work, please cite the following figshare entry.

@misc{moyo,
  author = {Kohei Shinohara},
  title  = {{moyo: A fast and robust crystal symmetry finder, written in Rust}},
  year   = {2026},
  month  = {1},
  doi    = {10.6084/m9.figshare.31081162.v1},
  url    = {https://figshare.com/articles/software/moyo_A_fast_and_robust_crystal_symmetry_finder_written_in_Rust_/31081162},
  note   = {Source code available at \url{https://github.com/spglib/moyo}}
}

This citation may be superseded by a peer-reviewed publication in the future.

cargo install cargo-release cargo-edit cargo-deny cargo-semver-checks

Prerequisites: cargo install cargo-release cargo-edit cargo-deny cargo-semver-checks

1. cargo semver-checks to lint a new release
2. cargo set-version --bump patch for patch version increment
3. Write change log and create a pull request
4. After merging the pull request, run cargo release --execute (If you already release the package in crates.io, run cargo release --execute --no-publish)
   • This automatically creates a git tag and pushes it to Remote, and triggers GitHub Actions to publish the packages.

RUST_LOG=debug cargo test -- --nocapture

We thank Dr. Yusuke Seto for providing the crystallographic database. We thank Dr. Juan Rodríguez-Carvajal for providing the magnetic space-group database.