Distributions of the samples of isomers based on specific order parameters. Panel a: two-dimensional distribution as a function of the sp² fraction and asphericity β. Panels b, c, and d: one-dimensional distributions as a function of isomer energy, number of 6-member cycles, and gyration radius, respectively. In panel a the boxes classify the four structural families, cage, planar polycyclic aromatic (PPA), pretzel, and branched; the same colors are used in panels b–d. Two example structures (numbered 1–8) are shown for each family.