Generative models such as GAs are known to generate molecules with unstable bonds and highly complex structures. Here, the score from the scoring function is modified by a synthetic accessibility measurement to steer the GA towards molecules with high catalytic activity and which are also synthesisable. The SA score as defined by Ertl and Schuffenhauer is used in connection with a modified Gaussian function as proposed by Gao and Coley which assigns molecules which are deemed easy to synthesise a value of up to 1 and molecules that are hard to synthesise a value of 0. The final score used in the GA is then obtained as the product of the electronic activation energy minus 100 and the modified SA score (with µ = 2.230044 and σ = 0.6526308).