Table 4. Relative Energies (kJ/mol) of the Five Structures in Figure 7 Calculated with Either r2SCAN or TPSSh and the Larger def2-TZVP Basis Set (TZ) or with the Original def2-SV(P) Basis Set (SV) and with the Surrounding Protein and Water Molecules Relaxed (Relax).
| DFT | protonation | BS | SV | TZ | SV-relax |
|---|---|---|---|---|---|
| r2SCAN | S2B(3) | 2467 | 0 | 0 | 0 |
| S2B(5) | 2467 | 9 | 7 | 20 | |
| Fe2 | 2358 | 26 | 26 | 29 | |
| S3A(5) | 2467 | 43 | 41 | 54 | |
| C3457 | 2468 | 61 | 64 | 62 | |
| TPSSh | S2B(3) | 1256 | 0 | 0 | 0 |
| S2B(5) | 1256 | 6 | –1 | 12 | |
| Fe2 | 2358 | 32 | 30 | 37 | |
| S3A(5) | 2468 | 42 | 31 | 46 | |
| C3457 | 1256 | 35 | 32 | 36 |