Table 11. rDSD Relative Electronic Energies, Harmonic Zero Point Energies, Thermal Contributions and Quasi-harmonic Corrections, together with Difference with JunChSF12 Electronic Energies and B3 Anharmonic Corrections (all in cm–1) for the Low-Lying Conformers of Aspartic Acida.
| Label | ΔErDSD | ΔChS | ΔZPEH | ΔThH | ΔZPE(anh–H) | TΔS(QH–H) | ΔG°b | ϕ′ | ψ | ω | χ1 | χ2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IIgt | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 36.3 | 20.7 | –6.3 | 61.7 | 168.8 |
| IIg–t | 133.5 | 7.5 | –57.1 | –60.8 | –13.1 | –9.7 | 0.3 | –35.7 | 20.0 | –4.3 | –65.5 | 174.7 |
| Igt | 288.7 | –4.3 | –143.6 | –80.1 | –17.3 | 7.0 | 50.4 | 179.6 | –164.5 | –177.8 | 67.8 | –177.2 |
| Ig–gc | 341.0 | –4.1 | 7.3 | –27.4 | –38.8 | –30.9 | 247.1 | 164.6 | 162.4 | 177.2 | –63.0 | 38.8 |
| III′gt | 350.5 | 83.5 | –114.2 | –99.3 | –13.7 | 27.3 | 234.1 | 177.0 | 24.4 | 178.1 | 65.9 | –179.7 |
| I′g–t | 478.9 | –40.6 | –178.2 | –121.6 | –24.5 | 9.1 | 123.1 | 86.6 | –167.5 | –177.0 | –63.9 | 169.8 |
| I′gg–c | 682.8 | 74.2 | –4.4 | 18.0 | –21.9 | 3.0 | 751.7 | 85.9 | –179.1 | –165.3 | 62.5 | –36.9 |
| IIItt | 777.4 | 9.7 | –86.0 | –25.3 | –12.7 | –65.0 | 598.1 | 169.6 | 5.1 | 167.2 | –158.3 | 171.1 |
| I′tt | 1136.3 | –17.7 | –202.4 | –193.0 | –17.3 | 51.1 | 757.0 | 62.7 | –179.5 | 58.6 | –173.7 | –160.1 |
b
Sum of columns 2, 3, 4, 5, 6, and 7.
a
Best estimates of relative free energies at room temperature (ΔG° in cm–1) and dihedral angles optimized at the rDSD level (ϕ′, ψ, ω, χ1 = N–Cα–Cβ–Cγ, and χ2 = Cα–Cβ–Cγ–O(H) in degrees) are also given. The χ3 angle (Cβ–Cγ–O–H) is always close to 180° (not explicitly indicated) or 0° (evidenced by the last “c” in the conformer label). See main text for details.