SpinForge is a group-theoretic generator for spin-symmetry-adapted (SSA) and oriented magnetic crystal structures based on spin space groups.

Installation

SpinForge supports Python 3.11 and later.

python -m pip install spinforge

For a source checkout and contributor setup, see CONTRIBUTING.md.

Quickstart: oriented magnetic structures

Given a primitive crystal structure in MnTe.cif, this example enumerates collinear SSA candidates with propagation-vector index one and generates every maximal oriented descendant:

from moyopy import Cell
from pymatgen.core import Structure
from spinspg.spin import SpinOnlyGroupType

from spinforge.configuration import SSAGenerator

structure = Structure.from_file("MnTe.cif")
prim_cell = Cell(
    basis=structure.lattice.matrix.tolist(),
    positions=structure.frac_coords.tolist(),
    numbers=list(structure.atomic_numbers),
)
magnetic_site_indices = [
    index for index, atomic_number in enumerate(prim_cell.numbers) if atomic_number == 25
]

generator = SSAGenerator(
    prim_cell=prim_cell,
    magnetic_site_indices=magnetic_site_indices,
)

for spin_only_group, spin_space_group, adapted_structure in generator.enumerate(
    spin_only_group_type=SpinOnlyGroupType.COLLINEAR,
    k_index=1,
    max_depth=0,
):
    oriented_structures = generator.generate_oriented(
        adapted_structure,
        spin_only_group=spin_only_group,
        nontrivial_spin_space_group=spin_space_group,
    )
    for magnetic_structure, magnetic_space_subgroup in oriented_structures:
        print(magnetic_structure.formula, magnetic_space_subgroup.msg_type)

SSAGenerator requires a primitive input cell. The family-subgroup, spin-space-group, and oriented spin-frame equivalence controls are separate. See the enumeration and equivalence guide for the precise criteria and the options for larger searches.

Examples

The paper examples are provided as notebooks in examples/paper:

• collinear MnTe
• coplanar Mn3Sn
• noncoplanar CoTa3S6

These examples are published as-is. The paper figures, MAGNDATA-derived datasets, and the raw 283-material SDFT workflow are not part of this repository.

Release flow

Releases are prepared by tagpr and published by the release GitHub Actions workflow.

1. Merge all changes for the release into main. Tagpr creates or updates the Release for vX.Y.Z pull request from its tagpr-from-v... branch.
2. Check out that pull request with gh pr checkout <number>, update its branch directly with the final release changes (including CHANGELOG.md), and push the commits to the same branch. Do not open another pull request for these changes.
3. If the proposed version needs to change, add the tagpr:minor or tagpr:major label to the release pull request; without either label, tagpr increments the patch version.
4. Review the generated release notes and wait for the release pull request's checks to pass, then merge it.
5. The resulting push to main makes tagpr create the version tag. The release workflow builds and verifies the wheel and source distribution, publishes them to PyPI, and creates the GitHub Release with both artifacts attached.

To rebuild an existing tag, run the release workflow manually with that tag. Set publish to false when the artifacts and GitHub Release should be rebuilt without publishing to PyPI.

Project scope, compatibility, and support

SpinForge provides symmetry enumeration, SSA and oriented-SSA structure generation, and spinCIF/MCIF-related utilities. It does not determine or refine magnetic structures from experimental or first-principles data, and it does not include scattering, electronic-structure, or high-throughput DFT workflows.

Compatibility

SpinForge supports Python 3.11 through 3.14. Beginning with version 1.0, documented interfaces re-exported by public SpinForge modules are kept compatible within the 1.x series. Names or modules with a leading underscore are private and may change without deprecation. Mathematical-validity, data-integrity, or security corrections are documented in the changelog when they require an exceptional incompatible change.

The spinCIF dictionary is preliminary upstream. SpinForge records the supported revision in spinforge.scif.SPINCIF_REVISION, and spinCIF syntax may evolve independently of the Python API policy.

Support

Please use GitHub Issues for reproducible bugs and in-scope feature requests. Security reports follow SECURITY.md.

Citation

If SpinForge contributes to published work, cite the software metadata in CITATION.cff and the associated oriented-spin-space-group paper:

T. Nomoto, K. Shinohara, H. Watanabe, and R. Arita, “Systematic magnetic structure generation based on oriented spin space groups: Formulation, applications, and high-throughput first-principles calculations,” Physical Review X (accepted 2026). doi:10.1103/8n3w-h2t1

@article{Nomoto2026SpinForge,
  author = {Nomoto, Takuya and Shinohara, Kohei and Watanabe, Hikaru and Arita, Ryotaro},
  title = {Systematic Magnetic Structure Generation Based on Oriented Spin Space Groups:
           Formulation, Applications, and High-Throughput First-Principles Calculations},
  journal = {Physical Review X},
  year = {2026},
  doi = {10.1103/8n3w-h2t1},
  note = {Accepted}
}

Data attribution and license

Third-party and literature-derived fixture notices are collected in docs/THIRD_PARTY_DATA.md, including all Materials Project fixtures and the MnTe and Mn3Sn source notices.

SpinForge source code is distributed under the BSD 3-Clause License. Third-party data retain the terms identified in their notices.