The chemical operation indices are defined as follows: index 0 is the atomwise conversion of a heteroatom into a carbon atom, index 1 is the atomwise removal of a terminal carbon atom, index 2 is the bondwise saturation, and index 3 is the bondwise removal of a saturated bond in a ring. The order of atom and bond indices for individual molecules has to be preserved to correspond to the correct atoms and bonds. The README and python script on Figshare 71 describe the order of atom and bond indices used during dataset generation. The python script can be used to extract ground truth explanations from any other chemical dataset similar to PCQM4Mv2 or for different chemical properties, as illustrated in Figures and. The generated ground truth explanation dataset does not consider the chirality, charge, or radicals of the molecules.