ONIOM calculation results for the electronic energy change for the cyclotrimerization of methyl isocyanatea.
| Computational levelb | ΔEec |
|---|---|
| B3LYP/cc-pVTZ | −61.3 |
| B3LYP-GD3/cc-pVTZ | −65.5 |
| B3LYP-GD3BJ/cc-pVTZ | −65.7 |
| MP2/aug-cc-pVDZ | −71.3 |
| MP2/cc-pVTZ | −70.5 |
| MP2/aug-cc-pVTZ | −71.0 |
| MP2/aug-cc-pVQZ | −70.5 |
a
Energy values are provided in kcal mol−1. Geometry optimizations were carried out at the B3LYP-GD3/cc-pVTZ level.
b
The computational levels that were applied to the outer layer in the ONIOM calculation are presented. The CCSD(T)/cc-pVTZ computational level was commonly applied to the inner layer.
c
The cyclotrimerization enthalpy at 298 K can be calculated by adding the enthalpy correction term to the electronic energy changes provided in the Table. The enthalpy correction term is +5.1 kcal mol−1.