The fitness of each gene is evaluated by attaching three copies to the triamidoamine core and generating a 3D structure using the ETKDG method in RDKit (using the embedding parameters found in Table ) where the coordinates of the core are constrained to match a DFT optimised structure. The core either includes the NH 3 , N 2 or NH 3 N 2 reacting moieties, depending on which intermediates are needed in the scoring function.