COMPASS force field

The consistent family of forcefields (CFF91, pcff, CFF and COMPASS) are closely related second-generation forcefields. They were parameterized against a wide range of experimental observables for organic compounds containing H, C, N, O, S, P, halogen atoms and ions, alkali metal cations, and several biochemically important divalent metal cations. pcff is based on CFF91, extended so as to have a broad coverage of organic polymers, (inorganic) metals, and zeolites. COMPASS (Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies) is the first forcefield that has been parameterized and validated using condensed phase properties in addition to various and empirical data for molecules in isolation. Consequently, this forcefield enables accurate and simultaneous prediction of structural, conformational, vibrational, and thermo physical properties for a broad range of molecules in isolation and in condensed phases.