BDE261: A Comprehensive Set of High-Level Theoretical Bond Dissociation Enthalpies

We have used the high-level W1w protocol to compile a
comprehensive
collection of 261 bond dissociation enthalpies (BDEs) for bonds connecting
hydrogen, first-row and second-row p-block elements. Together they
cover 45 bond types, and we term this the BDE261 set. We have used
these benchmark values to assess the performance of computationally
less demanding theoretical procedures, including density functional
theory (DFT), double-hybrid DFT (DHDFT), and high-level composite
procedures. We find that the M06-2X (DFT), ROB2-PLYP and DuT-D3 (DHDFT),
and G3X­(MP2)-RAD and G4­(MP2)-6X (composite) procedures yield absolute
BDEs with satisfactory to excellent accuracy. Overall, we recommend
G4­(MP2)-6X as an accurate and relatively cost-effective procedure
for the direct computation of BDEs. One important finding is that
the deviations for DFT and (especially) DHDFT procedures are often
quite systematic. This allows an alternative approach to obtaining
accurate absolute BDEs, namely, to evaluate accurate relative BDEs (RBDEs) using a computationally less demanding
procedure, and to use these RBDEs in combination with appropriate
and accurate reference BDEs to give accurate absolute BDEs. We recommend
DuT-D3 for this purpose. For a still less computationally demanding
approach, we introduce the deviation from additivity of the
RBDE (DARBDE), and demonstrate that the combination of lower-level
DARBDEs for larger systems and higher-level (W1w) reference RBDEs
and BDEs for small systems can be utilized to obtain improved RBDEs
for multiply substituted systems at low cost.