Table 7. 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 Threoninea.
| Label | ΔErDSD | ΔChS | ΔZPEH | ΔThH | ΔZPE(anh–H) | TΔS(QH–H) | ΔG°b | ϕ′ | ψ | ω | χ1 | χ2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IIgg | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | –33.7 | 21.8 | –6.1 | 60.0 | 77.1 |
| Ig–g | 218.5 | 34.5 | –85.9 | –83.0 | 27.7 | 20.4 | 132.2 | 162.5 | 143.7 | 177.8 | –55.4 | 42.4 |
| IItg– | 371.5 | 2.8 | 24.4 | 58.6 | 20.1 | –30.5 | 446.9 | –25.4 | 13.1 | –2.3 | –168.8 | –53.7 |
| I′gg– | 459.8 | –36.4 | –93.7 | 13.4 | 21.3 | –14.7 | 349.7 | 99.6 | –175.8 | –179.2 | 56.9 | –47.3 |
| III′g–g | 574.6 | 45.8 | –119.6 | –135.4 | 44.4 | 45.4 | 455.2 | 168.2 | –51.1 | –179.4 | –56.1 | 42.1 |
| III′gg | 624.2 | 10.8 | –76.8 | –62.6 | –37.4 | 4.4 | 462.6 | –170.6 | 72.6 | –176.4 | 57.8 | 65.8 |
| IIg–t | 711.2 | 9.2 | –68.8 | –25.5 | 7.5 | –8.1 | 625.5 | 35.1 | –21.0 | 5.4 | –54.6 | –177.8 |
| IIgtc | 586.1 | 6.9 | –137.1 | –104.9 | –48.5 | 9.5 | 312.0 | –26.2 | 11.5 | –2.6 | 50.1 | 161.2 |
| IIg–g– | 725.9 | 24.4 | –5.8 | –9.0 | 0.1 | –7.5 | 728.1 | 34.1 | –21.8 | 6.1 | –51.8 | –84.1 |
| Igtd | 962.3 | 8.8 | –242.2 | –137.4 | 4.0 | 8.4 | 603.9 | –172.7 | 178.6 | –179.4 | 64.0 | 179.4 |
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–O, and χ2 = Cα–Cβ–O–H in degrees) are also given. See main text for details.
b
Sum of columns 2, 3, 4, 5, 6, and 7.
c
Relaxes to IIgg.
d
Relaxes to Ig–g.