supercell-step 2025.6.25.1

A SEAMM plug-in for building supercells of periodic systems.

Supercell Step

A SEAMM plug-in for building supercells of periodic systems.

• Free software: BSD-3-Clause

• Documentation: https://molssi-seamm.github.io/supercell_step/index.html

• Code: https://github.com/molssi-seamm/supercell_step

Features

• Currently only accepts na, nb, and nc, the numbers of cells in the three directions.

• To do:

  • Create a supercell with a minimum dimension, e.g. 10 Å.

  • Create orthorhombic cells from hexagonal ones.

  • Build using the primitive cell rather than conventional.

Acknowledgements

This package was created with Cookiecutter and the molssi-seamm/cookiecutter-seamm-plugin project template.

Developed by the Molecular Sciences Software Institute (MolSSI), which receives funding from the National Science Foundation under award OAC-1547580 and CHE-2136142.

History

2025.6.25.1 – Bugfix: fixed crash caused by gradients.

• The addition of the gradients to the atom data caused a crash when expanding the cell. Since it doesn’t obviously make sense to expand the gradients, they are ignored when building a supercell.

2025.6.25 – Bugfix: avoid lowering symmetry for P1 systems.

2023.11.5 – Updated to handle symmetry in systems

2021.2.12 –

• Updated the README file to give a better description.

• Updated the short description in setup.py to work with the new installer.

• Added keywords for better searchability.

2021.2.4 –

• Updated for compatibility with the new system classes in MolSystem 2021.2.2 release.

2020.12.5 –

• Added support for non-orthorhombic cells.

• Updated to be compatible with the new system classes in MolSystem.

• Internal: switching CI from TravisCI to GitHub Actions, and in the process moving documentation from ReadTheDocs to GitHub Pages where it is consolidated with the main SEAMM documentation.

0.9.1 – 20 June 2020

• Bugfix: Was not properly copying charges to the new system.

0.9 – 18 June 2020

• First release on PyPI.

• Working but only for orthorhombic cells