CGenFF 2b8 can now be downloaded from the MacKerell lab's force field page. It introduces support for a few important functional groups, contains a number of fixes, and is compatible with the new version 0.9.7 beta of the CGenFF program at paramchem.org. Here is an incremental list of changes since CGenFF version 2b7 (copy-pasted from the CGenFF download page):
  • Introduced support for common saturated 4-membered rings through the model compounds cyclobutane (RESI CBU) and 2-azetidinone (RESI AZDO) and the new atom types CG3C41 and NG2R43
  • Added epoxide model compounds and parameters (RESI 1EOX and 1BOX and atom type OG3C31)
  • Added support for benzoic acid esters and derivatives through RESI ZOIC and MBOA
  • Added support for aliphatic nitro groups through RESI NIME and NIPR
  • Added sulfamate model compounds and parameters (RESI MSMT and PSMT)
  • Expanded support for neutral organic sulfonate through RESI PMST
  • Corrected wrongly transfered dihedral parameters for the hydroxyl hydrogen atom in alcohols - many compounds affected (problem reported by Xibing He)
  • Added model compounds for the drug hydrochlorothiazide: RESI OBTZ and APBT
  • Slight tweak of charges on RESI DMBU to fix minor inconsistency
  • Slight tweak in the following sulfonyl bond lenghts to improve agreement with crystal data: NG311-SG3O2, NG321-SG3O2, OG303-SG3O2
  • Fixed former "slack" dihedral parameter HGR62 CG2R62 NG2R61 HGP1 to improve hydrogen wagging in the vibrational spectrum of aromatic heterocycles
  • Improved transferability of CG2O5 CG311 OG311 angle
  • Improved transferability of OG2D2 CG2O3 CG311 CG2R61 dihedral
  • Fixed multiplicity problem for X CG311 NG2R53 CG2R53 dihedrals
  • Reserved MASS numbers for nearly-finished parametrization projects on terminal alkynes, azides, bipyrroles and hydroxamic acids
  • Modified a number of comments