naphthalene+OCH3+OCH3 C12H12O2
B_1e27057d54 · SMILES COc1ccc2ccc(OC)cc2c1 · InChIKey PPKHAIRFQKFMLE-UHFFFAOYSA-N
finite-difference Hessian noisy
finite-difference Hessian noisy (analytic check differs > 15 cm⁻¹). The finite-difference Hessian and the analytic Hessian of the same geometry differ by more than 15 cm⁻¹ on at least one frequency; the numerical route is the noisy one.Infrared spectrum at the cheap level (B3LYP/6-31G*, the pipeline's input)
How to read this
44 infrared-active bands (500–3500 cm⁻¹); the strongest at 1313 cm⁻¹ (7.6 µm), 352 km/mol.
cheap input (B3LYP): blue curve, sticks orange at the curve's peak scale. Lorentzian, FWHM 10 cm⁻¹; axis in km mol⁻¹ per cm⁻¹.
Band heights from the molecule's dipole derivatives and the same B3LYP Hessian as the listed positions (double harmonic).
Predicted spectrum (rung 3, the learned correction): computed by the pipeline, not drawn on this page; licensed for ring-ip, CH-stretch, CH-oop (decision 65).
How well is this shape known?
| measured on (ΔH network v1.3) | spectrum overlap cheap → corrected | height error cheap → corrected |
|---|---|---|
| 8 unseen simple aromatics (layer A), DFT stand-in for the higher level | 0.28 → 0.98 | 0.23 → 0.10 |
| 31 molecules of unseen scaffolds, DFT stand-in for the higher level | 0.37 → 0.97 | 0.51 → 0.24 |
| against coupled cluster | not measured for this version | |
Overlap: similarity of the two broadened spectra (1 = the same shape). Height error: relative error per band, weighted by height (0 = the same heights). "Corrected" is the learned correction on molecules it never saw; the pipeline serves it for the licensed families. Open: the dipole derivatives themselves are computed at the cheap level (on benzene they differ from coupled cluster by about 20 %).
Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)
72 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP; height = B3LYP band height (km/mol).
The B3LYP bands are drawn in the spectrum above; the table adds their heights, the ωB97X positions and the shift.
| # | B3LYP (cm⁻¹) | height (km/mol) | ωB97X (cm⁻¹) | shift |
|---|---|---|---|---|
| 1 | 60.6 | 4.33 | 81.7 | +21.1 |
| 2 | 82.8 | 2.02 | 97.9 | +15.1 |
| 3 | 125.5 | 2.27 | 137.6 | +12.1 |
| 4 | 153.9 | 0.91 | 162.6 | +8.7 |
| 5 | 156.9 | 1.78 | 165.6 | +8.7 |
| 6 | 239.4 | 1.58 | 233.4 | -6.0 |
| 7 | 241.3 | 0.01 | 248.7 | +7.4 |
| 8 | 244.7 | 0.05 | 271.5 | +26.9 |
| 9 | 312.4 | 0.80 | 322.2 | +9.8 |
| 10 | 324.8 | 2.33 | 336.9 | +12.1 |
| 11 | 345.4 | 4.47 | 351.3 | +5.9 |
| 12 | 377.0 | 0.01 | 381.7 | +4.8 |
| 13 | 445.1 | 0.01 | 456.8 | +11.6 |
| 14 | 454.4 | 4.94 | 460.3 | +5.9 |
| 15 | 483.0 | 7.07 | 486.8 | +3.8 |
| 16 | 515.8 | 0.86 | 523.3 | +7.4 |
| 17 | 558.8 | 13.55 | 565.1 | +6.3 |
| 18 | 622.6 | 0.36 | 638.1 | +15.5 |
| 19 | 646.3 | 4.92 | 648.9 | +2.6 |
| 20 | 654.9 | 0.01 | 668.7 | +13.8 |
| 21 | 694.6 | 0.86 | 699.7 | +5.1 |
| 22 | 752.2 | 2.28 | 766.0 | +13.8 |
| 23 | 779.0 | 17.37 | 787.6 | +8.6 |
| 24 | 793.4 | 9.05 | 802.2 | +8.8 |
| 25 | 797.0 | 1.75 | 809.1 | +12.1 |
| 26 | 837.8 | 7.33 | 850.9 | +13.0 |
| 27 | 841.9 | 40.64 | 859.0 | +17.1 |
| 28 | 885.8 | 44.59 | 902.0 | +16.2 |
| 29 | 939.5 | 0.49 | 966.3 | +26.8 |
| 30 | 960.7 | 0.30 | 979.2 | +18.5 |
| 31 | 970.6 | 4.40 | 991.7 | +21.1 |
| 32 | 980.3 | 10.73 | 993.4 | +13.1 |
| 33 | 1073.0 | 19.84 | 1091.8 | +18.8 |
| 34 | 1083.4 | 83.46 | 1102.6 | +19.2 |
| 35 | 1156.6 | 1.37 | 1162.8 | +6.2 |
| 36 | 1183.9 | 0.71 | 1174.0 | -10.0 |
| 37 | 1185.5 | 0.80 | 1187.7 | +2.3 |
| 38 | 1187.3 | 6.94 | 1188.9 | +1.6 |
| 39 | 1200.2 | 188.25 | 1203.3 | +3.0 |
| 40 | 1211.2 | 3.62 | 1215.1 | +3.9 |
| 41 | 1224.5 | 11.27 | 1228.5 | +4.0 |
| 42 | 1261.5 | 116.07 | 1264.4 | +2.9 |
| 43 | 1280.3 | 76.32 | 1295.0 | +14.7 |
| 44 | 1299.3 | 14.65 | 1307.0 | +7.8 |
| 45 | 1313.4 | 352.16 | 1319.3 | +6.0 |
| 46 | 1380.3 | 5.36 | 1389.2 | +8.8 |
| 47 | 1409.9 | 17.22 | 1400.7 | -9.3 |
| 48 | 1436.9 | 83.46 | 1442.7 | +5.8 |
| 49 | 1476.2 | 46.49 | 1491.2 | +15.0 |
| 50 | 1495.4 | 19.17 | 1503.0 | +7.5 |
| 51 | 1508.3 | 0.10 | 1520.8 | +12.5 |
| 52 | 1518.8 | 5.54 | 1526.8 | +8.0 |
| 53 | 1522.2 | 4.94 | 1533.5 | +11.3 |
| 54 | 1523.4 | 40.61 | 1535.8 | +12.4 |
| 55 | 1535.0 | 68.64 | 1541.5 | +6.6 |
| 56 | 1537.6 | 3.70 | 1544.2 | +6.6 |
| 57 | 1572.8 | 108.36 | 1600.0 | +27.2 |
| 58 | 1624.8 | 17.46 | 1656.3 | +31.5 |
| 59 | 1669.5 | 29.94 | 1696.7 | +27.1 |
| 60 | 1688.4 | 269.30 | 1733.2 | +44.8 |
| 61 | 3023.6 | 76.74 | 3060.0 | +36.5 |
| 62 | 3025.4 | 46.70 | 3061.5 | +36.1 |
| 63 | 3082.1 | 44.56 | 3130.5 | +48.4 |
| 64 | 3084.1 | 44.60 | 3132.5 | +48.4 |
| 65 | 3153.7 | 31.89 | 3197.1 | +43.4 |
| 66 | 3156.8 | 30.06 | 3200.0 | +43.2 |
| 67 | 3179.3 | 1.18 | 3224.1 | +44.9 |
| 68 | 3183.5 | 25.59 | 3226.7 | +43.2 |
| 69 | 3201.2 | 5.50 | 3245.4 | +44.2 |
| 70 | 3217.2 | 10.50 | 3260.6 | +43.3 |
| 71 | 3217.3 | 12.15 | 3262.6 | +45.3 |
| 72 | 3227.8 | 13.38 | 3272.7 | +44.9 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 17 cm⁻¹.
Provenance
- Releases: none yet
- Entered the corpus as: cores with one or two substituents, enumerated from the parents (layer B)
- Run: ubuntu-32gb-hel1-18, 2026-09-28 12:30:03 → 2026-09-28 13:44:17, 4454 s, peak 5.08 GB, deck 9e27bf8e9348
- Imaginary modes: B3LYP 0, ωB97X 0
- Cheap-level band heights: dipole derivatives dipole_b3lyp_cphf.npz, Hessian hessian_b3lyp.npz
- Source files: corpus factory · manifest