PySCF

The Python based Simulations of Chemistry Framework (PySCF) is a widely used quantum chemistry library, in chemistry and materials simulation, as well as in machine learning and quantum information theory. The aim of PySCF is not only to enable end-user simulations, but to facilitate the development of new methodologies and integration into complex workflows. The package is structured as a set of loosely coupled modules, implemented mainly in Python, and the code is designed to support molecular, materials, and model Hamiltonians on an equal footing.

Website: https://pyscf.org
Github: https://github.com/pyscf