Table 3.
Heterodimer binding energies (kcal/mol) and structures (Å) computed by AMOEBA and ab initio QM at different configurations (shown in Figure 1). The ab initio results were obtained at the level of MP2/Aug-cc-pvtz with BSSE unless otherwise noted.
| Configuration | Ab initio | AMOEBA | ||
|---|---|---|---|---|
| Distance | Eint | Distance | Eint | |
| Conf. A: | 1.65(O…H) | −17.39 | 1.74 (O…H) | −17.81 |
| CH3COO− - water (External) | ||||
| Conf. B: | 3.18 (C...O) | −20.99 | 3.18 (C…O) | −22.93 |
| CH3COO− - water (Bridge) | 1.96(O1…H1) | 1.96(O1…H1) | ||
| 1.96(O2…H2) | 1.96(O2…H2) | |||
| Conf. C: | 1.82(O…Zn) | −409.81a | 1.72(O…Zn) | −356.59 |
| CH3COO− - Zn2+ (External) | ||||
| Conf. D: | 2.25 (C…Zn) | 2.10 (C…Zn) | −442.30 | |
| CH3COO− - Zn2+ (Bridge)b | 1.90(O…Zn) | −425.80a | 1.81(O…Zn) | |
| Conf. E: CH3S− - water | 2.14(S…H) | −16.36 | 2.14 (S…H) | −21.30 |
| Conf. F: CH3S− - Zn2+ | 2.24(S..Zn) | −421.78 | 2.06 (S…Zn) | −391.76 |
| Conf. G: Imidazole - water | 1.91 (N…H) | −8.20 | 2.11 (N…H) | −8.10 |
| Conf. H: Imidazole – Zn2+ | 1.85 (N…Zn) | −175.55 | 1.75 (N…Zn) | −172.25 |
a
at the level of B3LYP6-311G**.
b
with C-O-Zn angle at 150º.