public_sql_50/table_descriptions.csv

table_name,table_description
molecule,"Stores one record per molecule with a unique text ID and its carcinogenicity classification. The molecule_id may include '+' (carcinogenic) or '−' (non-carcinogenic), while label explicitly states the status."
bond,"The bond table stores one record per chemical bond within a molecule, with bond_id (TRxxx_A1_A2) encoding the molecule and the two atoms involved. It links to the molecule via molecule_id and specifies bond order through bond_type (- single, = double, # triple). Stores one record per chemical bond within a molecule, including the bond type and an optional tag indicating the recording basis of the bond row."
connected,"Represents molecular bonds by linking two atom identifiers (atom_id and atom_id2) with a bond identifier (bond_id), enabling reconstruction of atom-to-atom connectivity. All fields are text IDs used to reference atoms and their connecting bond. Represents molecular bonds between pairs of atoms. Includes a directional flag that can distinguish alternative representations of the same linkage."
atom,"This table stores one record per atom, with a unique atom_id, the molecule_id of its parent molecule (atom IDs often follow TRXXX_i for the ith atom of molecule TRXXX), and the atom’s chemical element. Element values use standard symbols (e.g., C, H, O, N, S, Cl, P, Na, Br, F, I, Sn, Pb, Te, Ca)."
bond_record,"Stores bond-related records in a generalized format that can represent bond-level rows or atom-to-atom connection rows, depending on record_kind."