William L. Jorgensen is the C. P. Whitehead Professor of Chemistry at Yale University. Jorgensen is the developer of the Optimized Potentials for Liquid State (OPLS) potential functions for organic molecules (including proteins). He pioneered the methodology of developing potential functions by fitting parameters to reproduce the thermodynamic properties of pure liquids, which is now widely used by other workers. He authored the QikProp program for ADME property prediction. Other interests include calculation of the rates of chemical reactions of organic molecules in liquids, determination of protein-ligand binding energies via free energy perturbation theory, and methods for Monte Carlo simulations.