Open Force Field Toolkit A modern, extensible library for molecular mechanics force field science from the Open Force Field Initiative Getting started Installation Examples using SMIRNOFF with the toolkit Release History Frequently Asked Questions (FAQ) Using the toolkit Core concepts Cookbook: Every way to make a Molecule Cookbook: Using PDB files with the OpenFF Toolkit SMIRNOFF (SMIRks Native Open Force Field) Virtual sites Developing for the toolkit Molecule conversion to other packages API documentation Molecular topology representations Force field typing tools Toolkit Wrappers and Registries Utilities Exceptions