PCFF force field
PCFF is a member of the consistent family of force fields (CFF91, PCFF, CFF and COMPASS), which are closely related second-generation force fields. 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. It was developed based on CFF91 and its is intended for application to polymers and organic materials. It is useful for polycarbonates, melamine resins, polysaccharides, other polymers, organic and inorganic materials, about 20 inorganic metals, as well as for carbohydrates, lipids, and nucleic acids in calculations of cohesive energies, mechanical properties, compressibilities, heat capacities, elastic constants. It handles electron delocalization in aromatic rings by means of a charge library rather than bond increments.