Scoring components: Since we are interested in generating compounds that are active against the DRD2 target, the DRD2 activity model is added to the scoring function. Additionally, QED is included to prevent the model from generating molecules that have high predicted probability to be active but are not drug-like. For the task of molecular optimization, an extra scoring component, Tanimoto similarity based on RDKit Morgan fingerprints (radius = 2, with counts) is added to encourage generating molecules that are similar to corresponding input compound.