Computational BDE Dataset Curation: Efforts to construct generalizable models for BDE prediction of multiple bond types have been greatly enabled by the development of large computational datasets. Aires-de-Sousa and coworkers developed a dataset of computed BDE values for 1000 neutral molecules from the fragment-like subset of the ZINC database. Reference bond dissociation energies exclusive of zero-point vibrational energy (ZPE) were generated for 12,834 unique bonds (single and double) between C, H, N, O, and S at the B3LYP/6-311++G(d,p) level of theory. All geometries were optimized with the semi-empirical DFTB3 Hamiltonian. Subsequently, St. John and coworkers developed the BDE-db dataset, 22 taking 42,557 neutral CxHyOzNm molecules from the PubChem Compound database. This study used an automated fragmentation, conformer generation, and DFT computation workflow to obtain 290,664 unique ZPE-inclusive bond dissociation enthalpies at the M06-2X/def2-TZVP level of theory, which gave the best empirical performance when compared with values from the experimental iBond database. Motivated by energy storage and electrolyte applications, Persson and coworkers constructed the BDNCM dataset of 64,312 homolytic and heterolytic bond dissociations for 8,518 neutral and charged molecules containing C, H, O, F, and Li. BDFE values were obtained at the SMD-ωB97X-V/def2-TZVPPD level of theory. Additionally, DiLabio and coworkers have curated a high-quality benchmark dataset including 4502 datapoints of bond separation energies including H, B, C, N, O, F, Si, P, S, and Cl atoms at (RO)CBS-QB3 level of theory. In this work, we describe one of the most comprehensive quantum chemical bond dissociation datasets, BDE-db2, containing 531,244 unique homolytic BDE and BDFE values at the M06-2X/def2-TZVP level of theory (Fig. ). 332,035 unique dissociations absent from other datasets have been newly added. We included the ten most common elements in approved pharmaceuticals: C, H, O, N, S, Cl, F, P, Br, and I atoms (in order of their abundance). In addition to compounds originally sourced from PubChem present in BDE-db, we sourced 38,277 additional small molecules (10 heavy atoms or fewer) containing the above heteroatoms from the ZINC15 and PubChem compound libraries. M06-2X/def2-TZVP enthalpies (including the unscaled ZPE) and RRHO Gibbs energies (1 atm, 298K) were computed: the accuracy of this level of theory for halogenated molecules has been benchmarked, showing that hybrid functionals with a high proportion of exact exchange or long-range corrections are more accurate. An automated workflow generated the structures of parent and radical fragments from SMILES inputs by enumerating all possible exocyclic single-bond dissociations. Following conformational analysis with RDKit, the most stable conformers were optimized with DFT (further details in ESI Section 1). Structures with imaginary frequencies or having undergone structural rearrangements or fragmentations were removed. Further, recent studies highlighting unphysical and anomalous harmonic vibrations computed for open-shell species (with double-hybrid density functionals) led us to implement an additional filter for dissociations with abnormally large contributions from DZPE: 373 further dissociations with statistically significant deviations were removed in this way (ESI Section 1). The elemental and bond composition of the BDE-db2 dataset is shown in Fig. , which contains 806,433 bond-breaking reactions. After sampling chemical compounds in PubChem and ZINC15 randomly, the elements S, F, P, Cl, I, and Br are present in around 1.4% (22,385) of all bond dissociations alongside C, H, N, and O. The majority (54%) of bonds broken involve at least one carbon atom, with bonds to H the next most populous (35%). Bonds to carbon in all formal hybridization states and degree of substitution are well sampled (Fig. ). The frequency density of newly added bond types is shown in Fig. , with the highest number corresponding to C-S bonds (9165). Following this is C-F bonds with 8249. C-Cl, C-Br, and C-P bonds are around an order of magnitude less frequent than C-F bonds, while C-Br bonds are the most scarce, with 29.