We used publicly available positive ion mode mass spectra from the GNPS, MassBank and MatchMS online libraries. We shifted the m/z peaks of each spectrum to remove the adduct effect and discarded all spectra which resulted in peaks with negative mass or mass larger than the monoisotopic mass of the corresponding molecule, as well as all spectra with less than five peaks. We augmented this dataset with simulated mass spectra for a large set of molecules from ChEMBL, PubChem 33 and ZINC using the CFM-ID and FragGenie 14 predictors simulating the mass spectra at three different collision energies (10, 20 and 40 eV for CFM-ID, and building fragmentation trees with depths from one to three for FragGenie). All molecules were cleaned by removing chiral information and any charges. In total, we collected 10,750,283 molecules and 41,058643 spectra. Of these, 1,090,317 spectra were measured experimentally, corresponding to 51,417 molecules. We reserved 1% of the data (418,587 spectra / 107,398 molecules) for validation, such that the training set did not contain any spectrum of any molecule in the validation set.