naphthalene+CH3+CH3 C12H12
B_0e79b7f612 · SMILES Cc1cccc2c(C)cccc12 · InChIKey SDDBCEWUYXVGCQ-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
25 infrared-active bands (500–3500 cm⁻¹); the strongest at 808 cm⁻¹ (12.4 µm), 67 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)
66 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 | 98.5 | 0.32 | 96.9 | -1.6 |
| 2 | 168.4 | 0.06 | 169.1 | +0.8 |
| 3 | 192.2 | 0.00 | 174.0 | -18.2 |
| 4 | 196.6 | 2.29 | 204.8 | +8.2 |
| 5 | 209.0 | 0.00 | 215.0 | +6.0 |
| 6 | 261.6 | 0.44 | 264.8 | +3.2 |
| 7 | 272.0 | 3.68 | 273.1 | +1.1 |
| 8 | 333.1 | 0.00 | 335.6 | +2.6 |
| 9 | 466.9 | 0.00 | 472.3 | +5.4 |
| 10 | 468.6 | 0.00 | 479.6 | +11.0 |
| 11 | 482.0 | 0.00 | 495.8 | +13.7 |
| 12 | 493.3 | 1.30 | 498.1 | +4.8 |
| 13 | 518.6 | 0.00 | 521.9 | +3.3 |
| 14 | 536.2 | 5.27 | 539.5 | +3.3 |
| 15 | 583.3 | 0.87 | 589.2 | +6.0 |
| 16 | 644.1 | 0.00 | 651.2 | +7.1 |
| 17 | 645.9 | 0.00 | 660.9 | +15.0 |
| 18 | 751.5 | 0.00 | 757.1 | +5.6 |
| 19 | 798.8 | 2.49 | 803.2 | +4.5 |
| 20 | 807.7 | 66.63 | 820.8 | +13.1 |
| 21 | 823.8 | 0.00 | 839.6 | +15.8 |
| 22 | 865.5 | 0.00 | 874.0 | +8.5 |
| 23 | 893.5 | 1.37 | 905.2 | +11.7 |
| 24 | 901.6 | 0.28 | 923.4 | +21.7 |
| 25 | 913.5 | 0.00 | 934.3 | +20.8 |
| 26 | 971.3 | 1.20 | 1003.7 | +32.4 |
| 27 | 972.6 | 0.00 | 1004.1 | +31.5 |
| 28 | 1013.3 | 0.00 | 1019.2 | +5.9 |
| 29 | 1043.6 | 2.27 | 1043.7 | +0.1 |
| 30 | 1076.8 | 0.00 | 1084.5 | +7.7 |
| 31 | 1078.1 | 4.16 | 1086.0 | +8.0 |
| 32 | 1099.8 | 6.40 | 1099.7 | -0.1 |
| 33 | 1131.7 | 0.00 | 1139.2 | +7.6 |
| 34 | 1166.3 | 0.00 | 1179.5 | +13.2 |
| 35 | 1206.4 | 0.24 | 1198.1 | -8.2 |
| 36 | 1206.5 | 0.94 | 1213.3 | +6.8 |
| 37 | 1251.3 | 2.80 | 1242.3 | -9.0 |
| 38 | 1267.7 | 0.00 | 1280.4 | +12.8 |
| 39 | 1293.6 | 2.44 | 1303.6 | +10.0 |
| 40 | 1385.3 | 0.95 | 1375.3 | -10.0 |
| 41 | 1400.3 | 0.00 | 1408.0 | +7.7 |
| 42 | 1442.1 | 0.00 | 1450.8 | +8.7 |
| 43 | 1444.4 | 0.60 | 1453.9 | +9.6 |
| 44 | 1455.3 | 0.23 | 1465.9 | +10.6 |
| 45 | 1455.9 | 17.11 | 1468.7 | +12.8 |
| 46 | 1513.5 | 0.00 | 1517.6 | +4.1 |
| 47 | 1515.3 | 8.03 | 1517.6 | +2.3 |
| 48 | 1515.3 | 4.72 | 1532.1 | +16.9 |
| 49 | 1528.3 | 18.37 | 1533.3 | +4.9 |
| 50 | 1536.2 | 0.00 | 1543.1 | +6.8 |
| 51 | 1566.2 | 8.54 | 1597.3 | +31.2 |
| 52 | 1642.5 | 0.00 | 1678.0 | +35.4 |
| 53 | 1659.3 | 13.02 | 1684.3 | +25.0 |
| 54 | 1675.2 | 0.00 | 1717.9 | +42.7 |
| 55 | 3039.2 | 52.65 | 3075.8 | +36.6 |
| 56 | 3039.5 | 7.26 | 3076.1 | +36.7 |
| 57 | 3088.8 | 0.02 | 3140.3 | +51.6 |
| 58 | 3088.8 | 41.14 | 3140.4 | +51.6 |
| 59 | 3126.4 | 2.00 | 3174.0 | +47.6 |
| 60 | 3126.5 | 35.38 | 3174.1 | +47.6 |
| 61 | 3176.3 | 25.08 | 3220.2 | +43.9 |
| 62 | 3177.0 | 0.24 | 3220.8 | +43.8 |
| 63 | 3193.4 | 2.89 | 3237.2 | +43.7 |
| 64 | 3193.6 | 47.15 | 3237.2 | +43.7 |
| 65 | 3215.3 | 30.36 | 3259.6 | +44.3 |
| 66 | 3216.0 | 10.93 | 3260.4 | +44.3 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 32 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-hel1-21, 2026-09-27 23:36:18 → 2026-09-28 00:36:05, 3586 s, peak 4.57 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