OpenMM. Examples of the scripts used for both the liquid and gas simulations along with input files for all molecules in the study can be found in the Supporting Information. The uncertainties were found to be less than 0.003 g/cm 3 and 0.02 kcal/mol for densities and heats of vaporization respectively. Graphs showing the convergence of the properties with simulation time can also be found in Figures and.