Here, p i is the probability for the selection of individual i, r i is the rank of individual i and N is the number of individuals in the population. Individuals with low scores will have a high probability of being selected for mutation/crossover operations. After the mutation/crossover operation, the new individual has to contain one tertiary amine and has to have more than 5 but less than 14±6 heavy atoms, otherwise, it is discarded. Duplicates are removed after 100 new individuals are generated and the 100 best-performing individuals from the current and the previous generation advance to the next generation.