Development of an Accurate and Robust Polarizable Molecular Mechanics Force Field from ab Initio Quantum Chemistry

We have produced a polarizable force field for a series of small molecules, representative of functional groups found in organic and biochemical systems. We have used high-level ab initio results for fitting values of all the parameters except for the dispersion-term coefficient B in the −B/r6 energy term, which, although obtained from comparison with experimental condensed-phase data, depended only on atomic number of the site in hand. Heats of vaporization and densities of the pure liquids, computed with molecular dynamics, agreed with experiment within ca. 0.5 kcal/mol and 5%, respectively.