A common measure of the quality of FF parameters for use in biomolecular simulations is a comparison of the predicted condensed phase properties of molecules simulated using the FF with experiment. These properties, such as liquid density, the heat of vaporization and free energy of hydration, can be calculated routinely due to low sampling requirements, thus making FF inaccuracies the main contributor to any differences between the computed data and experiment. In this study, we have chosen a benchmark dataset comprising 109 small organic molecules, which are representative of the key functional groups commonly observed of the FFs. Figure shows the results of the condensed phase property calculations for the test set where experimental data are available, along with the correlations and mean unsigned errors (MUE), while Table compares the latter with some examples of widelyused transferable FFs for the same test set. The average errors in the density and heat of vaporization (0.024 g/cm 3 and 0.79 kcal/mol, respectively) indicate that QUBE performs extremely well in the prediction of pure liquid properties, that is despite only using eight fitting parameters in the derivation of non-bonded parameters (the van der Waals radii of the elements H, C, N, O, S, F, Cl, Br used in this study). Table lists thirteen molecules the used for fitting and shows that removing them from the validation set has negligible effect on the analysis. Some of the outliers in the heat of vaporization predictions include interactions between aromatic rings, which may be due to the difficulty of describing van der Waals interactions using a simple r -6 interaction, which neglects higher-order dispersion and many-body effects. The general transferable force fields are of similar accuracy to QUBE, despite being extensively parametrized against data sets similar to these.