To obtain the necessary parameters for the IL CG models, atomistic MD simulations were conducted for each fragment. These simulations provided the bonded parameters and solvent accessible surface area (SASA) values essential for accurate model construction. In the absence of experimental data for the fragments, we also used COSMO-RS, a quantum chemistry-based method, to predict the thermodynamic properties . This approach has consistently been recognized as one of the best prediction tools for oil/water partitioning data . An additional advantage of COSMO-RS is its ability to predict logP for not only the octanol/water but also for other partitioning systems, which is crucial for the chemical transferability of the Martini CG models. In this work, we used all three gold standard partitioning systems employed in Martini 3 parametrization: octanol/water, hexadecane/water, and chloroform/water. We also ensured consistency across both the fragment library and the existing phospholipid library. For some fragments, compromises on the CG partitioning free energy were necessary to maintain consistency and transferability within the library. It is worth noting that COSMO-RS typically has an mean absolute error (MAE) range of 2-3 kJ/mol , which justifies our preference for maintaining internal consistency with the Martini bead assignment rather than perfectly matching the free energies.