• Physicochemical attributes: A property of special interest is the molecular weight since it is directly reflected in the mass spectrum. In particular, the spectra indicates the mass of the fragments and therefore the mass of the original, non-fragmented, molecule can be approximated more easily given the mass spectra as opposed to determining the composition or the structure of the molecule. We record the difference between the molecular weight of the generated structures and the reference structure and we report the relative average minimum difference, that is, the average-minimum difference over all the predicted structures divided by the average molecular weight of the reference structures (DM W min ). We also report the average-average difference over all the predicted structures divided by the average molecular weight of the reference structures (DM W avg ). Additionally, we also evaluate whether the model is able to identify the element composition of the molecule.