Optimization against densities and enthalpies of mixing led to significant changes in many of the LJ parameters after refitting, detailed in Figure . These changes, as detailed below, provide clear evidence of improved prediction of condensed phase properties. Overall, almost all new values of LJ 𝑅 𝑚𝑖𝑛∕2 and 𝜀 are within ±5% and ±10% of the Parsley 1.3.0 values, respectively. Exceptions include the 𝑅 𝑚𝑖𝑛∕2 for [#35:1] (Br), which decreased significantly. This decrease is associated with a correction in bromide densities in vdw-v1, which were generally underpredicted relative to experiment in Parsley 1.3.0. The reduction in 𝑅 𝑚𝑖𝑛∕2 and therefore, molecular volume, leads to an increase in densities after the optimization that corrects the underprediction. The dramatic correction in densities for bromides and bromide-containing mixtures after optimizing the LJ parameters is illustrated in Figure , Panel A.