Open Force Field Software

The Open Force Field Initiative is creating molecular mechanics force fields for simulation of large biomolecular systems, and the tools to use them easily and accurately. OpenFF force fields are optimized automatically and in the open, with open source tools, from open source datasets. We assign parameters directly to chemical graphs without the intermediate step of assigning atom types, and we can export parametrized systems to a host of simulation engines.

Getting Started

Instructions for installing and using OpenFF software can be found at Installation and in the project-specific documentation below. If you want to understand how to use OpenFF force fields, or if you want to see what’s possible, see Modelling with OpenFF or the Examples.

Standards

Specifications for SMIRNOFF and other standards defined by OpenFF can be found at OpenFF Standards.

Projects

openff-toolkit

Tools for preparing systems and manipulating force fields

openff-interchange

Parametrize and export systems ready for simulation to various MD engines

openff-units

Unified units of measure handling for the OpenFF ecosystem based on Pint

openff-bespokefit

Automated parameter optimization for specific molecules or series of molecules

openff-qcsubmit

Submit and retrieve datasets with rich metadata from QCFractal instances

openff-fragmenter

Fragment molecules for efficient quantum mechanical torsion scans

openff-evaluator

Scalably and automatically estimate physical properties

openff-recharge

Generate optimized partial charges for molecules with a variety of methods

openff-nagl

Train and use machine-learned partial charge models targetting molecular graphs

Contact Us

Need help? Raise an issue on GitHub, open a discussion on OpenFF Discussions, or email us!