Pure liquid properties were calculated by simulation in the NPT ensemble, at the temperature and pressure from the corresponding physical property reference. These were performed with the default OpenFF Evaluator simulation workflow, in which a box of 1000 molecules of the target substance were placed in a simulation box using PackMol , with parameters then assigned using the OpenFF Toolkit version 0.6.0 . An energy minimization and 0.2 ns equilibration run were then performed using OpenMM. Subsequently, the molecules were simulated for 2 ns. For all simulations, a Langevin integrator with BAOAB splitting and a 2 fs timestep, and the default OpenMM Monte Carlo barostat, were employed to ensure simulation in the correct NPT ensemble. Uncorrelated and well-equilibrated snapshots were used to compute the ensemble averages of any observables, according to the procedure outlined by Chodera . All uncertainties in the average observables were computed by bootstrapping with replacement, and propagated through any further calculations, assuming a Gaussian error model. Densities are estimated using ensemble averages from these simulations.