Open Force Fields

Force fields produced by the Open Force Field Initiative

smirnoff99Frosst

Status: Experimental License: CC-BY 4.0

A minimalist AMBER-compatible general small molecule force field with excellent coverage of druglike chemical space, using the SMIRNOFF direct chemical perception specification.

[Preprint] | [GitHub] | [Download]

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.