Gemmi

GEMMI can help if you work with:

• macromolecular models (from mmCIF, PDB and mmJSON files),
• refinement restraints (CIF files) and small molecule models,
• crystallographic reflections (from MTZ and SF-mmCIF files),
• electron and other density maps (MRC/CCP4 files),
• crystallographic symmetries,
• or if you just read and write CIF/STAR files (where C=Crystallographic).

GEMMI is a C++ library (currently, C++14) accompanied by:

• command-line tools,
• Python bindings,
• Fortran 2003+ interface (in progress),
• partial WebAssembly bindings,
• online tools molecular viewer GemmiMOL and little data viz projects.

Documentation: http://gemmi.readthedocs.io/en/latest/

GEMMI is an open-source project of CCP4 and Global Phasing Ltd, two major providers of software for macromolecular crystallography.

Citing: JOSS paper.

License: MPLv2, or (at your option) LGPLv3. © 2017-2025 Global Phasing Ltd.