the fingerprint-based similarity. The similarity distribution along with the summary statistics in Figure indicate that Maybridge, ChemDiv, CRAFT, and Enamine were the most diverse fragment libraries, followed by Life Chemicals, and the NP-based fragment libraries COCONUT and LANaPDB. The NPbased fragments were the least diverse, which was unexpected. This could be because of the vast number of fragments and the data variability that are being studied. The distribution of the data is in a considerably wider range and the curve is pushed towards greater similarity compared to the reference libraries. Figure shows the cumulative distribution function and summary statistics of the pairwise Tanimoto similarity using Morgan2 (1024-bit) and MACCS keys (166-bit) fingerprints for the "Fragment RO3." The data sets are color-coded using the same colors as in Figure . The cumulative distribution function and summary statistics indicate that, in general, the COCONUT, Maybridge, ChemDiv, CRAFT, and LANaPDB were the most diverse "Fragments RO3" libraries, followed by Life Chemicals and Enamine. It is interesting to note that the distribution of the PNs is the most diverse and the most similar when looking at the results for the fragments and "Fragment RO3", respectively (Figures and). This suggests that focusing on the "Fragments RO3", they capture a sizable portion of the diversity of the NPs. Notably, the structural diversity of the fragment libraries, as captured by the fingerprints, is still large and it is not compromised or restricted by the RO3 rules.