SEARS

SEARS is the Stereochemically Expanded Autooxidation Reaction Space dataset associated with Ref. 1. It contains stereochemically resolved data for alkylperoxy-to-hydroperoxyalkyl isomerization reactions,

ROO• → •QOOH

with a focus on diastereomeric transition-state pairs in low-temperature hydrocarbon autooxidation.

Repository contents

rdkit-codes/

The rdkit-codes directory contains the RDKit-based scripts used for SMILES collection, stereochemical enumeration, radical generation, and SMILES manipulation, as described in Fig. 2 of Ref. 1.

data-all/

The data-all directory contains CSV files with electronic energies, SMILES strings, transition-state identifiers, and IRC-related descriptors for the SEARS reaction dataset.

sears2356.csv

Data for 2,356 transition-state structures, corresponding to 1,178 ROO• → •QOOH reactions. These transition states retain the intended covalent-bond connectivity after DFT optimization. See Fig. 3 of Ref. 1.

sears2324.csv

Data for the IRC-validated subset of 2,324 transition-state structures, corresponding to 1,162 ROO• → •QOOH reactions. In this subset, the IRC path is consistent with the intended ROO• and •QOOH connectivity. See Fig. 4 of Ref. 1.

Column descriptions of sears2356.csv and sears2324.csv

Column	Meaning
TS_ring	Ring size of the cyclic transition-state scaffold for the intramolecular H-transfer. For example, 5 means a five-membered cyclic TS motif.
RH_name	Identifier for the parent hydrocarbon.
RH_smiles	SMILES string of the parent hydrocarbon.
RH_Eele_TZVP	Electronic energy of the parent hydrocarbon at the ωB97M-D4/def2-TZVP level.
Rrad_name	Identifier for the alkyl radical generated from the parent hydrocarbon.
Rrad_smiles	SMILES string of the alkyl radical, R•.
Rrad_Eele_TZVP	Electronic energy of the alkyl radical at the ωB97M-D4/def2-TZVP level.
Rrad_Eele_def2SVP	Electronic energy of the alkyl radical at the ωB97M-D4/def2-SV(P) level.
ROO_name	Identifier for the alkylperoxy radical generated by O₂ addition to R•.
ROO_smiles	SMILES string of the alkylperoxy radical, ROO•.
ROO_Eele_TZVP	Electronic energy of ROO• at the ωB97M-D4/def2-TZVP level.
ROO_Eele_def2SVP	Electronic energy of ROO• at the ωB97M-D4/def2-SV(P) level.
QOOH_name	Identifier for the hydroperoxyalkyl radical formed by intramolecular H-transfer from ROO•.
QOOH_smiles	SMILES string of the hydroperoxyalkyl radical, •QOOH.
QOOH_Eele_TZVP	Electronic energy of •QOOH at the ωB97M-D4/def2-TZVP level.
QOOH_Eele_def2SVP	Electronic energy of •QOOH at the ωB97M-D4/def2-SV(P) level.
TS_name	Identifier for the transition-state structure connecting the corresponding ROO• and •QOOH species.
TS_smiles	SMILES representation of the cyclic TS scaffold. The [N] atom is a placeholder for the transferring H atom used during structure generation.
TS_Eele_TZVP	Electronic energy of the transition state at the ωB97M-D4/def2-TZVP level.
TS_Eele_def2SVP	Electronic energy of the transition state at the ωB97M-D4/def2-SV(P) level.
IRC_npoints	Number of points reported along the IRC energy profile.
IRC_Efirst	Relative energy of the first IRC point, typically in kcal/mol relative to the TS energy.
IRC_Elast	Relative energy of the last IRC point, typically in kcal/mol relative to the TS energy.
IRC_Emin	Minimum relative energy along the reported IRC profile.
IRC_Emax	Maximum relative energy along the reported IRC profile; usually 0.0 because the TS is the reference.
bondsbroken_IRC_F	Number of bonds from the cyclic TS scaffold that are broken in the forward IRC endpoint connectivity.
bondsbroken_IRC_B	Number of bonds from the cyclic TS scaffold that are broken in the backward IRC endpoint connectivity.
IRC_energies	Semicolon-separated list of relative IRC energies, usually in kcal/mol, with the TS energy set to 0.0.

Other assorted data

The repository also includes additional data organized by workflow level:

• data-level-1-smiles: SMILES strings for all generated species.

• data-level-2-smiles-rdkitgeom: RDKit-generated geometries corresponding to the SMILES structures.

• data-level-3-smiles-dftgeom: DFT-optimized geometries for the corresponding species.

References

1. Raghunathan Ramakrishnan,
   A Chemical Space Perspective on Diastereomeric Barriers in Alkylperoxy-to-Hydroperoxyalkyl Isomerization,
   preprint, 2026.