The Open Forcefield Toolkit provides implementations of the SMIRNOFF format, parameterization engine, and other tools. Documentation available at http://open-forcefield-toolkit.readthedocs.io

Fragment molecules for quantum mechanics torsion scans

Bayesian tools for fitting molecular mechanics torsion parameters to quantum chemical data.

Utilities for determining maximum tolerable timesteps. See https://doi.org/10.3390/e20050318