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MolSym

A python package for handling molecular symmetry.

Capabilities

• Point group detection
• Molecule symmetrization
• Symmetry element generation
• Character table generation
• SALC generation for atomic basis functions, internal coordinates, and cartesian coordinates

Installing

We recommend installing MolSym into its own environment. For example, with conda:

conda create -n "NameYourEnvironment" python=3.X

conda activate "NameYourEnvironment"

MolSym is available on PyPI and can be installed with pip:

pip install molsym

MolSym is also available on conda-forge and can be installed with conda:

conda install -c conda-forge molsym

MolSym is tested with Python 3.10–3.14. Some features rely on the optional QCElemental dependency, which can be pulled in with:

pip install "molsym[qcel]"

Development installation

To work on MolSym itself, clone the repository and install it in editable mode:

git clone https://github.com/NASymmetry/MolSym.git # or git@github.com:NASymmetry/MolSym.git

cd MolSym

pip install -e .

Include the optional QCElemental-backed features with:

pip install -e ".[qcel]"