The ligand dictionary for the PDB was downloaded in a SMILES format from the RCSB website. RDKit was used to parse the strings and detect ring sizes, as well as removing metals and inorganic species. Boettcher scores were used to provide a metric for molecular complexity, and calculated using previously reported code. Representative ligands were sampled for each ring size, and the PDB was queried for their complexes with proteins. From that, we curated a small representative set of macrocyclic complexes matching the following criteria: deposited Xray crystal structure agreed with the chemical structure of the reported ligand; resolution <= 3.5 Å; and no cofactors in the binding site. The final set contains 90 ligands.