Fig. 4

Encoding and decoding process: Encoding The reactants and products of the mapped reaction are aggregated into a pseudo-molecule. The bond changes are annotated: green for a bond order change, blue for a bond made, and red for a bond broken. All atoms and bonds are annotated as part of the reaction center (inside blue circle), remaining in the final product (green circles), or leaving the final product (yellow circle). Finally, all atoms and bonds are encoded into ReactionCode by layers starting from the reaction center to the outermost layer. Decoding: The ReactionCode is transformed into a pseudo-molecule, which allows one to recover the initial reaction