OpenFF Toolkit 0.16.9+d20250429 documentation

openff-toolkit

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