Table 1. Best Estimates for the Relative Energies of the Expanded Porphyrin Database (in kcal mol–1)a.
| CCSD(T)/cc-pVDZ | CCSD(T)/CBS | CCSD(T)/cc-pVDZ-F12 | CCSD(T)/CBS | |
|---|---|---|---|---|
| extrap scheme | none | MP2/cc-pV{T,Q}Z + [CCSD(T) – MP2]/cc-pVDZ | MP2-F12/cc-pVDZ-F12 + [CCSD(T) – MP2]/cc-pVDZ | MP2/heavy-aug-cc-pV{T,Q}Z + [CCSD(T) – MP2]/cc-pVDZ |
| 24Ha | 9.12 | 7.92 | 8.06 | 7.82 |
| 24Hb | 0.00 | 0.00 | 0.00 | 0.00 |
| 24M | 6.06 | 6.38 | 6.48 | 6.35 |
| 24TS1 | 9.05 | 8.93 | 9.01 | 8.83 |
| 24TS2 | 4.87 | 5.12 | 5.18 | 5.07 |
| 28H | 0.00 | 0.00 | 0.00 | 0.00 |
| 28M | –0.73 | –1.77 | –1.75 | –1.64 |
| 28M1A | 0.46 | 0.28 | 0.28 | 0.46 |
| 28M1B | 1.82 | 1.39 | 1.39 | 1.57 |
| 28F | –0.38 | 0.16 | –0.08 | 0.29 |
| 28TS1A | 6.33 | 4.65 | 4.58 | 4.70 |
| 28TS1B | 2.86 | 2.00 | 1.92 | 2.05 |
| 28TS2A | 6.87 | 6.10 | 6.02 | 6.29 |
| 28TS2B | 9.89 | 8.88 | 8.79 | 9.07 |
| 28TS3 | 5.17 | 4.50 | 4.36 | 4.60 |
| 32F | 0.00 | 0.00 | 0.00 | 0.00 |
| 32Ma | 16.81 | 15.45 | 15.65 | 15.13 |
| 32Mb | 16.74 | 16.59 | 16.52 | 16.45 |
| 32H | 34.60 | 32.59 | 32.72 | 32.16 |
| 32TS1 | 17.49 | 16.08 | 16.16 | 15.78 |
| 32TS2 | 33.79 | 32.33 | 32.36 | 31.97 |
| RMSD | 0.95 | 0.10 | 0.19 | |
| MUE | 0.74 | REFERENCE | 0.08 | 0.14 |
| MaxD | 2.01 | 0.23 | 0.43 |
a
The CCSD(T)/CBS energies were obtained from extrapolation of the MP2 energies at the complete basis set limit from the (heavy-aug-)cc-pVTZ and (heavy-aug-)cc-pVQZ basis sets. Alternatively, the CCSD(T)/cc-pVDZ-F12 were estimated from explicitly correlated MP2-F12/cc-pVDZ-F12 calculations.