quinoxaline C8H6N2
A_7aa232d4e9 · SMILES c1ccc2nccnc2c1 · InChIKey XSCHRSMBECNVNS-UHFFFAOYSA-N
Anchored analytic check agrees
Infrared spectrum at the anchor level (CCSD(T)/cc-pVDZ + [DF-MP2 psi4 1.10.2 (cc-pvtz-jkfit / cc-pvtz-ri, frozen 10): cc-pVTZ − cc-pVDZ]; rung 4, anchored)
Band heights: not computed for this molecule yet (no dipole derivatives); positions only. Compared with the cheap Hessian (B3LYP, analytic): frequency rms 18.4 cm⁻¹.
Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)
42 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP.
Both functionals are drawn in the anchor chart above; the table lists the values of the corpus.
| # | B3LYP (cm⁻¹) | ωB97X (cm⁻¹) | shift |
|---|---|---|---|
| 1 | 177.0 | 186.1 | +9.1 |
| 2 | 184.8 | 203.7 | +18.9 |
| 3 | 397.9 | 404.4 | +6.5 |
| 4 | 416.1 | 429.4 | +13.3 |
| 5 | 480.9 | 495.4 | +14.5 |
| 6 | 502.5 | 512.4 | +9.9 |
| 7 | 535.2 | 537.5 | +2.3 |
| 8 | 544.1 | 549.7 | +5.6 |
| 9 | 616.1 | 618.4 | +2.4 |
| 10 | 653.4 | 668.3 | +14.9 |
| 11 | 773.7 | 783.3 | +9.5 |
| 12 | 778.2 | 786.1 | +7.9 |
| 13 | 814.4 | 830.2 | +15.8 |
| 14 | 850.2 | 854.3 | +4.1 |
| 15 | 887.8 | 907.5 | +19.7 |
| 16 | 896.5 | 913.2 | +16.7 |
| 17 | 965.3 | 975.4 | +10.0 |
| 18 | 975.9 | 1002.9 | +27.0 |
| 19 | 984.5 | 1013.6 | +29.1 |
| 20 | 1003.8 | 1029.6 | +25.8 |
| 21 | 1039.0 | 1043.5 | +4.5 |
| 22 | 1057.2 | 1057.6 | +0.4 |
| 23 | 1155.2 | 1155.8 | +0.6 |
| 24 | 1173.0 | 1158.9 | -14.1 |
| 25 | 1242.6 | 1232.1 | -10.5 |
| 26 | 1249.7 | 1253.4 | +3.7 |
| 27 | 1297.1 | 1301.6 | +4.5 |
| 28 | 1339.7 | 1332.4 | -7.3 |
| 29 | 1401.1 | 1407.9 | +6.8 |
| 30 | 1425.0 | 1433.3 | +8.4 |
| 31 | 1464.5 | 1471.3 | +6.8 |
| 32 | 1514.3 | 1532.5 | +18.2 |
| 33 | 1548.8 | 1577.5 | +28.7 |
| 34 | 1618.3 | 1654.7 | +36.5 |
| 35 | 1619.1 | 1658.9 | +39.9 |
| 36 | 1671.9 | 1708.4 | +36.5 |
| 37 | 3162.6 | 3207.1 | +44.6 |
| 38 | 3180.5 | 3224.3 | +43.8 |
| 39 | 3190.8 | 3233.1 | +42.3 |
| 40 | 3203.3 | 3245.7 | +42.4 |
| 41 | 3216.8 | 3259.8 | +43.1 |
| 42 | 3220.9 | 3263.5 | +42.6 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 3 cm⁻¹.
Provenance
- Releases: layerA2_2026-09-23, layerA2_2026-09-23b, layerA2_2026-09-24, layerA_2026-09-22
- Entered the corpus as: parent molecules chosen by hand (benzene, naphthalene, the PAH cores and their relatives) (layer A)
- Coupled-cluster anchor: CCSD(T)/cc-pVDZ + [DF-MP2 psi4 1.10.2 (cc-pvtz-jkfit / cc-pvtz-ri, frozen 10): cc-pVTZ − cc-pVDZ]
- Anchor spectrum: Hessian composite_quinoxaline.npz
- Run: ubuntu-32gb-hel1-2, 2026-09-18 20:12:52 → 2026-09-18 20:32:53, 1201 s, peak 2.71 GB, deck 97ed2d67c66b
- Imaginary modes: B3LYP 0, ωB97X 0
- Source files: corpus factory · manifest