We experimented with two approaches to assigning roles to the molecules found in a reaction (e.g., whether a molecule is a reactant or an agent): trusting the labeling of molecules in ORD (referred to as "labeling") or applying chemical reaction logic to identify the role of different molecules from the reaction string (referred to as "rxn string" or "reaction string"). Our reaction logic identified reactants (molecules that contribute atoms to the product(s)) and spectator molecules (molecules that do not contribute atoms to the product(s)) based on the atom-mapping and their position in the reaction SMILES string. Solvents were identified in the list of spectator molecules by cross checking Figure : We present two different approaches for handling rare molecules. Rare ! "other" is investigated as a strategy to avoid deleting reactions with rare molecules. against a list of solvents compiled from prior research (see Appendix B.1.1), while all other spectator molecules are marked as agents.