Table 2. Our Best Estimates for the Relative Isomer Energies Considered in This Worka.
| system | CCSD(T)/cc-pVDZ | MP2/cc-pV{T,Q}Z + [CCSD(T)-MP2]/cc-pVDZ | MP2-F12/cc-pVDZ-F12 + [CCSD(T)-MP2]/cc-pVDZ |
|---|---|---|---|
| 24Ha | 9.12 | 7.92 | 8.06 |
| 24Hb | 0.00 | 0.00 | 0.00 |
| 24M | 6.06 | 6.38 | 6.48 |
| 24TS1 | 9.05 | 8.93 | 9.01 |
| 24TS2 | 4.87 | 5.12 | 5.18 |
| 28H | 0.00 | 0.00 | 0.00 |
| 28M | –0.73 | –1.77 | –1.75 |
| 28M1A | 0.46 | 0.28 | 0.28 |
| 28M1B | 1.82 | 1.39 | 1.39 |
| 28F | –0.38 | 0.16 | –0.08 |
| 28TS1A | 6.33 | 4.65 | 4.58 |
| 28TS1B | 2.86 | 2.00 | 1.92 |
| 28TS2A | 6.87 | 6.10 | 6.02 |
| 28TS2B | 9.89 | 8.88 | 8.79 |
| 28TS3 | 5.17 | 4.50 | 4.36 |
| 32F | 0.00 | 0.00 | 0.00 |
| 32Ma | 16.81 | 15.45 | 15.65 |
| 32Mb | 16.74 | 16.59 | 16.52 |
| 32H | 34.60 | 32.59 | 32.72 |
| 32TS1 | 17.49 | 16.08 | 16.16 |
| 32TS2 | 33.79 | 32.33 | 32.36 |
a
The latter were obtained at the MP2/cc-pV{T,Q}Z + [CCSD(T)-MP2]/cc-pVDZ and MP2-F12/cc-pVDZ-F12 + [CCSD(T)-MP2]/cc-pVDZ levels of theory, with p functions on H omitted. All entries are in kcal mol–1.