Issues

• Use maintained version of python-constraint

  openforcefield/openff-toolkit#2246 · Filter by author mattwthompson opened on Oct 6, 2026
  1

• Docs not building as part of PR checks

  openforcefield/openff-toolkit#2243 · Filter by author j-wags opened on Sep 25, 2026

• vdWType.rmin_half / vdWType.sigma modification easily breaks force field hashing

  bug
  openforcefield/openff-toolkit#2241 · Filter by author mattwthompson opened on Sep 24, 2026

• Topology.from_pdb is extremely slow on solvated protein with rdkit> 2024.09.6

  openforcefield/openff-toolkit#2240 · Filter by author fjclark opened on Sep 23, 2026
  2

• Improve import times

  openforcefield/openff-toolkit#2237 · Filter by author mattwthompson opened on Sep 16, 2026
  

• "stable" docs point to 0.18.0

  openforcefield/openff-toolkit#2232 · Filter by author mattwthompson opened on Sep 9, 2026
  2

• Visualization test extremely slow

  openforcefield/openff-toolkit#2200 · Filter by author mattwthompson opened on Jun 12, 2026

• Raise lower dependency constraints

  openforcefield/openff-toolkit#2192 · Filter by author j-wags opened on Jun 3, 2026
  2

  

• Revamp testing environments

  openforcefield/openff-toolkit#2184 · Filter by author mattwthompson opened on May 15, 2026
  

• Treat AmberTools as an optional dependency

  openforcefield/openff-toolkit#2179 · Filter by author mattwthompson opened on May 13, 2026
  1

  

• Molecule.to_inchi does not fall back through wrapped toolkits as expected

  bug
  openforcefield/openff-toolkit#2172 · Filter by author mattwthompson opened on Apr 21, 2026
  

• Add Topology.solvate

  api extension
  openforcefield/openff-toolkit#2171 · Filter by author mattwthompson opened on Apr 10, 2026
  6

  

• mmCIF/PDBx support

  openforcefield/openff-toolkit#2159 · Filter by author whmidgley opened on Mar 5, 2026
  1

• Misleading error message for adding a duplicate VirtualSite parameter

  openforcefield/openff-toolkit#2157 · Filter by author lilyminium opened on Feb 25, 2026

• Isomorphism comparisons are (still) slow on similar large molecules (tautomer)

  openforcefield/openff-toolkit#2155 · Filter by author FinnOD opened on Feb 23, 2026
  1

  

• Support installing with pip

  openforcefield/openff-toolkit#2154 · Filter by author peastman opened on Feb 18, 2026
  2

• [nonblocking] aromaticity_model doesn't propagate

  api breaking
  openforcefield/openff-toolkit#2152 · Filter by author jaclark5 opened on Feb 18, 2026
  2

• assign_partial_charges does not pass the toolkit_registry argument to openff-nagl

  openforcefield/openff-toolkit#2149 · Filter by author lilyminium opened on Feb 9, 2026
  1

  

• Molecule.to_file(..., file_format='pdb') with OpenEye produces a PDB file without elements

  openforcefield/openff-toolkit#2148 · Filter by author Yoshanuikabundi opened on Feb 3, 2026
  1

• Inconsistency between OpenMM simulation run with interchange AMBER and serialized OpenMM system files

  openforcefield/openff-toolkit#2136 · Filter by author spencercguo opened on Dec 15, 2025
  12

  

• Some tests are slow

  openforcefield/openff-toolkit#2132 · Filter by author mattwthompson opened on Dec 12, 2025

• NAGLToolkitWrapper warning thrown when not using NAGL

  openforcefield/openff-toolkit#2131 · Filter by author IAlibay opened on Dec 10, 2025
  2

  

• Latest versions (toolkit 0.17, interchange 0.4.6) don't work in GoogleColab

  openforcefield/openff-toolkit#2103 · Filter by author pbuslaev opened on Sep 6, 2025
  7

• Requesting guidance on opening small molecules

  openforcefield/openff-toolkit#2102 · Filter by author David-OConnor opened on Sep 5, 2025
  9

• Update wording on AM1BCC charge assignment

  openforcefield/openff-toolkit#2098 · Filter by author j-wags opened on Aug 22, 2025
  1