easychem 2.1.0

Equilibrium chemistry computation tool

easyCHEM: a Python package for calculating equilibrium chemistry abundances of exoplanet atmospheres

Welcome to the easyCHEM repository. easyCHEM is a Python package for calculating chemical abundances in exoplanet atmospheres, assuming equilibrium chemistry. Ancillary outputs are the atmospheric adiabatic temperature gradient and mean molar mass. easyCHEM is a clone of the equilibrium chemistry part of NASA’s CEA code, written from scratch and with numerical stability in mind. In particular, the code implements the equations described in Gordon & McBride (1994) and makes use of LAPACK’s dgesv routine for fast matrix inversion. Since we incorporated the dgesv source code into easyCHEM, users do not require external math libraries.

Documentation

The code documentation, installation guide, and tutorial can be found at https://easychem.readthedocs.io.

Attribution

If you use easyCHEM in your work, please cite the following articles:

• for the easyCHEM base implementation: Mollière et al. 2017.

• The JOSS paper (Lei & Mollière) is in prep.

License

Copyright 2022-2025 Elise Lei and Paul Mollière

easyCHEM is available under the MIT license. See the LICENSE file for more information.

dgesv, which is part of LAPACK, and which easyCHEM is using, is available under the BSD license.