Table 8.
The A-A’ atomic energy terms of CO2H and CO2− groups in various chemical environments (kJ/mol). The average values are given in the last row for the anions only, with the standard deviation in brackets. Method: 2PDM-M/CCSD(T)/uncontracted 6–31 + G(d, p). Grid is (15,15)
| Molecule | C | O(= C) | O(-H) or O−(-C) |
H | sum | C | O(= C) | O(-H) or O−(-C) |
H | sum |
|---|---|---|---|---|---|---|---|---|---|---|
| HCO2H (reference) | 126.9 | 193.0 | 177.6 | 22.5 | 520.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| HCO2− (reference) | 130.2 | 192.8 | 192.8 | 515.8 | 0.0 | 0.0 | 0.0 | 0.0 | ||
| HCO2−. H2O | 129.0 | 192.2 | 192.2 | 513.4 | −1.2 | −0.6 | −0.6 | −2.3 | ||
| HCO2−.(H2O)2 | 127.0 | 190.0 | 191.3 | 508.3 | −3.3 | −2.7 | −1.5 | −7.5 | ||
| CH3CO2H | 135.7 | 196.9 | 178.4 | 23.3 | 534.4 | 8.8 | 3.9 | 0.8 | 0.8 | 14.3 |
| CH3CO2− (conf. A) | 134.7 | 195.3 | 194.0 | 524.0 | 4.4 | 2.5 | 1.3 | 8.3 | ||
| CH3CO2− (conf. B) | 135.5 | 194.7 | 194.7 | 524.8 | 5.2 | 1.9 | 1.9 | 9.0 | ||
| CH3CO2−.H2O | 138.4 | 194.9 | 193.8 | 527.1 | 8.1 | 2.2 | 1.1 | 11.4 | ||
| C2H5CO2H | 136.9 | 197.0 | 179.2 | 23.6 | 536.7 | 10.0 | 4.0 | 1.5 | 1.1 | 16.6 |
| C2H5CO2− | 136.0 | 195.0 | 194.1 | 525.1 | 5.7 | 2.3 | 1.3 | 9.3 | ||
| Average (SD) anions | 133.0 (3.9) | 193.6 (1.8) | 193.3 (1.1) | 519.8 (6.7) | 3.2 (4.0) | 0.9 (1.9) |
0.6 (1.2) |
4.7 (7.0) |