As the number of negative links in the graph is very high, we sampled a subset of the negative links for computational feasibility. To generate this subset, first a set of reactants pairs were sampled by drawing 1,000 random unique reactants in the graph. Each of these unique reactants were combined with all other reactants in the graph which participated in at least five reactions (26,846 reactants) to create a set of negative links. This sampling procedure has been reproduced three times for statistical consistency, creating three sets with unique unobserved reactions. The probabilities for the unobserved reactions have been predicted by the SEAL model. The reactant pairs with a predicted reaction probability above 0.95 were then passed through the Chemformer model to predict products for the proposed reactions. In Table , the number of unobserved reactions in each set and the number of predictions above 0.95 is reported. The results shows that most of the predicted reactions generates unique products and that most of the generated product are novel, as ~0.1-0.2% are also a product in USPTO.