Therefore, the representative of the largest cluster was taken as the first fragment. Next, the representative from the next largest cluster is added to the selection only if their Tanimotosimilarity based on the FCFP4 fingerprint is below 0.75. Furthermore, an R-group decomposition of their substructure matches in the leadlike subset of the REAL Space S was performed for all fragments. All except one exit vector must have at least ten small (≤ 7 heavy atoms) substituents available to achieve full sociability. This led to a 96-membered "Core library".