Chempath is a pathway analysis program that automatically builds the the most important pathways of a reaction system. This algorithm was originally developed by Lehmann (2004). Chempath is an open-source, python implementation of this algorithm.

Chempath is described in this paper: https://doi.org/10.5194/gmd-18-4433-2025

Clone this repository with and go to the repository main directory.

Create a conda environment with the packages necessary to run chempath:

conda create --name chempath python=3.10

Activate the environment and install the required packages with:

conda activate chempath
pip install -r requirements.txt

Try running the tests:

python chempath_tests.py

You can use this conda environment within a jupyter notebook with:

conda install -c anaconda ipykernel
python -m ipykernel install --user --name=chempath

If there are no errors, you can go ahead and use Chempath.

• See the tutorial jupyter-notebook to learn how to use Chempath.
• See an example of how to use Chempath in a photochemical box model
• See an example of how to use Chempath in a 1D photochemical model

Lehmann (2004): An Algorithm for the Determination of All Significant Pathways in Chemical Reaction Systems, Journal of Atmospheric Chemistry, 47, 45–78.

Garduno Ruiz (2025): Chempath 1.0: an open-source pathway analysis program for photochemical models. https://doi.org/10.5194/gmd-18-4433-2025