Hyperparameters. ChemSpacE does not entail many hyperparameters, the only important one is the manipulation range which is critical to the exploration degree of the latent space. For molecule manipulation experiments, as we would like a gradual change over the molecular structure and property, we set the range as [-1, 1]. While for molecule optimization task, it requires more aggressive exploration strategies to reach the expected latent area which poses optimal property values. We utilize [-100, 100] and for single property optimization and multi-property optimization experiments respectively. We report the results for single property optimization with ranges from in Table .