Evaluating Force Fields Using Wolf2pack's Molecular Database

Force fields are a fundamental element in molecular mechanics (MM) based methods, such as molecular dynamics (MD) simulations. Being able to quantitatively assess existing force-field, reoptimize parameters found to be questionable, and optimizing new parameters is critical for performing reliable MD simulations and in evaluating the resulting data. We have developed Wolf₂Pack (W₂P) that allows us to do these things. W₂P is a collection of scripts that allows us to efficiently generate quantum mechanic target observables (i.e. relative energies, geometries, electrostatic potentials) and generate their corresponding MM observables for direct comparison. An important component of W₂P is its molecular database that allows us to explore diverse chemical motifs and enables a high degree of reproducibility and transparency in the raw data. In this talk I will discuss how we use W₂P and its database to evaluate exiting force fields in order for users to better understand their strength and possible weaknesses. For example, we will show the degree of dependencies that MM relative potential energies have upon the choice of partial atomic charges (e.g. AMBER's RESP versus AM1-BCC, Glycam06's charges for force-field development versus those used its database of carbohydrate residues.)