Since these structures are built from their underlying net, we tried to perform the opposite operation on the Predicted Crystallography Open Database (PCOD) to assess our implementation. This database contains 331,172 CIF files representing zeolites with energies within 30 kJ/mol (per SiO 2 unit) of α-quartz, which were analyzed by CrystalNets.jl in 45 minutes using 20 cores (Intel Xeon Silver 4210R CPUs, 2.4 GHz). Bond guessing forced O atoms to have at most 2 neighbours, which is the default heuristic for O atoms not bound to metals: this incidentally ensures that all vertices of the net correspond to Si atoms.