Notes. We added a column, $k_{\text{Eckart}}^{50}$, denoting the rate constant at 50 K (s⁻¹) computed using an asymmetric Eckart fit to the barrier in Reaction (R11) with or without CPCM correction. All values are reported at the revDSD-PBEP86(D4)/jun-cc-pV(T+d)z level including and not including implicit solvent corrections. The A(B) notation symbolizes A× 10^B.^(a)Calculated from the bimolecular system as $\text{Δ}{H}^{\text{R}}=H_{\text{Prod}}-\left(H_{{\text{CH}}_3}{}_{\text{CO}}+H_{\text{H}}\right)$ ^(b)Barrierless. ^(c)Unimolecular rate constants obtained using a reactant state at large CH₃CO and H distance, as converging a pre-reactant complex was impossible due to the barrierless channels present nearby.