Introduction¶

This documentation describes the pythmpg software that can be used to create user-customized spreadsheets as part of the Python MPG project. See the User Guide for an overview of the project. Note that some pre-constructed spreadsheets are provided at the Zenodo Pyth-MPG site; these can be used without the need to reference the software described here.

The source for this documentation and the pythmpg software package is the pythmpg GitHub repository.

Example Script for Spreadsheet Creation¶

The top-level entry point for most users is the Spreadsheet class, which drives construction and export of a .csv spreadsheet whose rows and columns correspond to magnetic point groups (MPGs) and symmetry-allowed properties respectively. Here is a minimal workflow using all defaults:

from pythmpg import Spreadsheet
sheet = Spreadsheet()
sheet.header_report()          # optional: inspect column layout
sheet.build_csv()              # compute tensor counts for every MPG
sheet.write_csv('mpg.csv')

Example Scripts for Direct Access¶

Direct access to the symmetry information, without reference to any spreadsheet structure, is also provided by two functions get_mpg_info() and get_num_indep() from the mpg_tools module.

Query symmetry info for a subset of groups:

from pythmpg import get_mpg_info
info = get_mpg_info(['4/mmm', 'm-3m'])
info['order']
# [16, 48]

Count independent components of a rank-2 symmetric tensor:

from pythmpg import get_num_indep
count_dict = get_num_indep(['[V2]'], mpg_list=['1', 'm', '4/mmm'])
count_dict
# {'[V2]': [6, 4, 2]}

Modules in the Package¶

spreadsheet: Defines Spreadsheet, the primary user-facing class.
mpg_tools: Functions get_mpg_info() and get_num_indep() for querying MPG symmetry properties and tensor independence counts.
mpg_dicts: Module-level dictionaries describing all 122 MPGs, their generators, and BNS serial numbers. Built on first import.
pg_elements: Constructs rotation matrices and multiplication tables for the hexagonal and cubic crystallographic point groups.
parse_jahn: Parser for Jahn symbols that encodes index-symmetrization instructions for arbitrary-rank tensors.

Installation¶

PythMPG is available through PyPI:

pip install pythmpg

To install from source in editable mode:

git clone https://github.com/pythmpg/pythmpg.git
cd pythmpg
pip install -e .

PythMPG ≥ 1.0.0 requires Python ≥ 3.12 and numpy ≥ 2.0

Citation¶

If you use the code in your paper, please cite us. Here is a bibtex entry:

@software{Urru_Python_Magnetic_Point_2026,
author = {Urru, Andrea and Birol, Turan and Cole, Trey and Vanderbilt, David},
doi = {10.5281/zenodo.18672613},
license = {GPL-3.0-or-later},
month = jun,
title = {{Python Magnetic Point Group (PythMPG)}},
url = {https://zenodo.org/records/18672613},
version = {1.0.0},
year = {2026}
}

License¶

This software is released under the GNU General Public License v3.0.