Surface tension. Historically, surface tension was not considered as part of the target data in the force field parameterization process. It is therefore not surprising that water models published before 2005 exhibited poor agreement with the experimental surface tension (Figure ). In contrast to density and coordination number, the Ewald correction to the TIP-family models did not significantly improve the surface tension. One notable exception was the PCFF force field, which had one of the closest values to experiment of any water model studied here. This is most likely due to the Lennard-Jones epsilon value for the oxygen, which is the largest of any water model in this study. It is known that epsilon values generally correlate positively with surface tension, and one force field parameterization strategy is to simply scale all epsilon values until the experimental surface tension is reproduced. 130 However, this is not the only factor, as one of the best models for surface tension, TIP3P-ST, has one of the smallest epsilon values of any model tested in this work. The analytical tail correction to the surface tension due to the Lennard-Jones cutoff, which generally increases the value of the calculated surface tension by ~3-4 mN/m, 108 was not performed in this study, as it has been shown recently to perhaps overestimate the surface tension by ~2 mN/m. Nevertheless, the surface tension has been shown to increase as the Lennard-Jones cutoff is increased, and by extrapolating to an infinite cutoff, the TIP3P-ST model was found to have a surface tension within 1 mN/m of the experimental value, while in this study it was found to be ~8 mN/m below the experimental value. Therefore, despite appearing to systematically underestimate the surface tension (Figure ), nearly all models published in 2005 or later can be considered to reproduce the experimental surface tension reasonably well, with the TIP4P/Ice and a99SB-disp overestimating the surface tension somewhat. Long-range corrections to the Lennard-Jones interactions, similar to long-range corrections to the electrostatics like PPPM and PME, may improve the calculated surface tension as well. The absence of ions and dissolved gas in the simulated systems could also contribute to a lower surface tension compared to experiment. For additional discussion of the use of surface tension as target data in force field parameterization, we refer the reader to the publication of the TIP3P-ST and TIP4P-ST models. Dielectric constant. Liquid water exhibits a high dielectric constant, εs, that is unique amongst most polar liquids. The macroscopic dielectric constant contains information on the collective orientational correlations between molecules and their permanent dipole moments, where the dielectric constant is directly linked to the strength of dipolar forces between water molecules. Computationally, the dielectric constant can be readily accessed from the total dipole moment of the system, M, via