4. The clustering stage was conducted based on the exclusion spheres method. Here, molecules exhibiting a minimum similarity above a specified cut-off (Tanimoto above 0.35) were grouped together into clusters. Each molecule identified as a member of a cluster was flagged and subsequently removed from further comparisons. Molecules that remained unflagged at the end of the clustering process were designated as singletons. These singletons may have neighbors at the given Tanimoto similarity index, but these neighbors would have been excluded by a stronger cluster centroid.