In the Supplementary Note 12.3, we show that with the training of only 500 samples, we can get a reasonable estimate of the HOMO-LUMO gap of the molecules in the QMugs dataset. Also, by reverting the question, we have our model trained for inverse design. In Supplementary Note 12.3, we show that by asking the model What is a molecule with a HOMO-LUMO gap of 3.5 eV, we get similar to the photoswitches, a set of novel molecules. These novel molecules are not part of our training set and not even part of the QMugs dataset.