A graph-based genetic algorithm (GA) is used to obtain tertiary amines that induce a low activation barrier (the energy difference between TS3 and the reactants) in the MBH reaction and hence a low score (further details on the scoring function in the next section). The GA is run for 100 generations with a population size of 100, the starting population is chosen randomly from a subset of tertiary amines from the ZINC database . New individuals are created with a 50:50 chance either by mutation or crossover operations performed on molecules from the previous generation. The molecular sites for crossover and mutations are selected at random and thus offer a free exploration of chemical space. Individuals are selected for mutation/crossover operations with a probability proportional to their rank within the population (rank selection). Here, individuals are ranked in descending order based on their score (low score to high rank) and their probability for selection is calculated following Baker with a selective pressure (SP) of 1.5: