def get_molecule_hash(self, mol):
        """
        Return inchi as molecular hash
        """
        obconv = ob.OBConversion()
        obconv.SetOutFormat(str("inchi"))
        obconv.AddOption(str("X"), ob.OBConversion.OUTOPTIONS, str("DoNotAddH"))
        inchi_text = obconv.WriteString(mol)
        match = re.search(r"InChI=(?P<inchi>.+)\n", inchi_text)
        return match.group("inchi")