This mechanism has adopted a series of new reaction rates and rate rules mostly from recently reported high-level calculations.
The H2 and H2+ channels were minimal compared to H+. H3+ formation was not observed in our CASSCF trajectories due to the limited sampling afforded by these high-level calculations and the low H2 formation yield.
Recent high-level calculations have shown conclusively that the NIR absorption in these molecules is not due to the increased donation and acceptance but is due to the diradicaloid nature of the central oxyallyl ring.
Extensive global minimum searches, followed by high-level calculations and Gibbs free energy corrections, reveal that at least three 2D isomers, I (C1, 2A), II (C1, 2A), and III (C1, 2A), could contribute to the observed PE spectrum for the B26− cluster.
High-level calculations assign the unusually complex spectrum of a molecular pair implicated in interstellar chemistry.
Modern, high-level calculations can take hours or days to compute using fast computers.
In general, the best approach will be to calculate free energy profiles at a low level and correct them using high-level calculations.
The reliability of the MP2/aug-cc-pVDZ method for the present dimers was demonstrated by performing high-level calculations for the benzene⋅⋅⋅1,3,5-triazine complex.
DFT was selected for high-level calculations on pragmatic reasons because it requires overall less computational overhead than ab initio methods and performs adequately.
The results of higher level calculations on smaller clusters were used to estimate corrections to the MP2/6-31G*//HF/6-31G* energies.
For the highest level calculations, B3LYP/6-311+G*//HF/4-31G*, the barrier for rotation about a CC bond is ∼10 kJ mol−1 and ∼30 kJ mol−1 about a CO bond.
