using the previous version of the force field, which takes octanol-water transfer free energies as a target. Molecules that were parametrized in the main publication on Martini 3 were tested against transfer free energies between several solvents and water, namely octanol, hexadecane, and chloroform . This improves the parametrization of a molecule with respect to its wide range of chemical properties. Following this approach and because experimental values were not available for each fragment, reference values were calculated by using COMSO-RS. Overall, a good correlation is visible for the hexadecane-water and chloroform-water values, with a similar R 2 value. In contrast, the octanol-water values show a low correlation. To further investigate the octanol-water case, reference values were recalculated using ALOGPS , a neural network that can predict octanol-water partitioning coefficients. These values are shown in Figure in the supporting information. Compared to the COSMO-RS val-ues, they result in a slightly better correlation (R 2 = 0.363), but it is still relatively low in contrast to the hexadecane-water and chloroformwater values. Of the three solvents considered for the transfer free energies, octanol is the least hydrophobic. As a result, the range of free energy values is narrower. In addition, many of the molecules considered are similar in terms of the functional groups present, which also results in a smaller range of free energy values. This could explain the lower correlation of the octanol-water values compared to the values with the other solvents. It should also be noted that methods such as COSMO-RS can only provide limited accuracy. They are suitable for analyzing general trends in the free energies for different solvents, but could also contribute to additional scattering of the values. In general, the match with the reference could be improved by slightly adjusting the choice of beads. However, for the current set of molecules, this proves to be a time-consuming task. Also, not only the free energy should be taken into account, but also the exact properties of the functional groups, which can vary depending on the individual structure of a molecule (e.g. change of polarity of Ketone groups in caffeine ). It is assumed that, despite deviations in the free energy values, the standard assignment used in this work provides an adequate initial description of the molecules. Any adjustments regarding the assignment of the beads could be addressed in future studies.