DESPOTIC is a library to Derive the Energetics and SPectra of Optically Thick Interstellar Clouds. Its capabilities include calculating spectral line luminosities from clouds of specified physical properties and compositions, predicting line profiles, calculating rates of heating and cooling due to a wide range of processes, determining clouds' equilibrium gas and dust temperatures, and calculating time-dependent thermal evolution of clouds.

DESPOTIC is implemented as a Python package, and is released under the GPL. The physical model, equations solved, and some tests and example applications are described in Krumholz (2014).


Full documentation for DESPOTIC is hosted at readthedocs.

Downloading DESPOTIC

DESPOTIC is distributed in two ways. The full source distribution, including example Python programs using it and sample cloud descriptor files, is available from


and can be obtained via git by doing

git clone

Despotic is also available through the python package index. If you have pip installed, you can just type

pip install despotic

The tarball may also be downloaded from PyPi and installed using the standard Python distutils method.