2022-09-29 Force Field Release Meeting notes

water models, non-mainline FFs, and calendar versioning in openff-forcefields?

Matt Thompson (backup Jeff Wagner)

continuing from 2022-09-14 Meeting notes

• Seems to be strong consensus for switching the repo “version” to “calendar versioning”, where releases are of the form 2022.09.14 instead of 2.0.0. The file names would remain unchanged (Sage = openff-2.0.0, Rosemary = openff-3.0.0, etc), but the git tags, python module, and conda packages would reflect the “calendar version” instead of the “force field version”.

• How to version “ports” of external FFs/FFs whose reference implementations are defined elsewhere?

• Would we want to add different ion models as well? Would we bundle them with compatible water parameters? How would we define compatible?

Different parameters applied to chemically equivalent atoms

Lily Wang

• Specific SMIRKS patterns matching single or double bonds apply differently to chemically equivalent atoms such as nitro groups

• Suggested fix (by PB): create new, less specific patterns