I can't believe it's NonAbelian!

A general purpose library to study vibrational problems using diffusion monte carlo

NITROGEN is a Python package for rovibronic calculations for small molecules.

The Concordant Mode Approach utilizes lower level of theory normal modes to compute higher level force constants at a fraction of the cost!

Library that handles atom structures as XYZ files and properties derived from it.

Open-Source Quantum Chemistry – an electronic structure package in C++ driven by Python

Parallel finite difference optimization and hessians from arbitrary single point energies

Fermi quantum chemistry program

Automated Generation of Machine Learning Models of Molecular Potential Energy Surfaces

Arbitrary-order derivatives of popular electronic structure methods, such as Hartree-Fock and coupled cluster theory.