As a sanity check, we evaluated the ability of the pre-trained AE to reconstruct the SMILES of the molecules in the testing set of the spectra dataset. We recall that the AE has been pre-trained on molecular structures derived from the PubChem database while the molecules in the spectra dataset are from the NIST database. The molecules from the NIST dataset were not used for pre-training the AE, although it is expected that a portion of the NIST molecules is present in the PubChem database which is used for pre-training.