QM9 database contains computed properties of over 134 000 molecules made up of 9 atoms of C, O, N and F. Molecules included in the database were picked from GDB17 chemical universe . The computations were conducted on B3LYP/6-31G(2df,p) level of theory. The source of the QM9 database was MoleculeNet website. Recently, the database was extended by Lim et. al. with compounds containing Cl and S atoms chosen from GDB17. Independently to QM9-extended database we also made an effort to extend the QM9 database. To achieve this objective, a number of SMILES were generated and quantum-chemistry calculations were conducted with Psi4 open source quantum chemistry calculations software. The process is described in next section. Quantum properties included in the QM9, QM9extended databases and whether they were calculated with Psi4, are listed in Table . The final substructures database was a combination of QM9-extended and our own QM9 extension.