Next, we used FastROCS to generate an allby-all matrix of 3D Tanimoto combo scores for all the building blocks (including enumerated stereoisomers) in each library position. We iterated over each conformer of each building block to identify the highest possible shape and color overlap between every pair of compounds. Thus, each entry (i, j) of the 3D Tanimoto combo matrix represented the largest possible overlap in both shape and color between any conformer of compound i and any conformer of compound j. For compounds with multiple stereoisomers, we identified a single stereoisomer that gave the highest similarity to other compounds. To do so, we first enumerated all stereoisomers for the compound and evaluated the similarity of a given stereoisomer to all other compounds. We then selected the stereoisomer that gave the highest average similarity to all other compounds and discarded the rest. Associated code for these steps can be found at 4.4.1.