Open Force Fields
Force fields produced by the Open Force Field Initiative
A minimalist AMBER-compatible general small molecule force field with excellent coverage of druglike chemical space, using the SMIRNOFF direct chemical perception specification.
This force field achieves comparable accuracy to GAFF in physical properties, but with with a decrease in complexity from over 6000 lines of parameters to only ~300 lines using the SMARTS-based direct chemical perception possible with SMIRNOFF. This force field is intended to be a starting point for rapid cycles of automated optimization to rapidly improve accuracy for modeling protein - small molecule interactions.