naphthalene+CH3+CH3 C12H12
B_0424c4ffc2 · SMILES Cc1ccc2ccccc2c1C · InChIKey QNLZIZAQLLYXTC-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
50 infrared-active bands (500–3500 cm⁻¹); the strongest at 3193 cm⁻¹ (3.1 µm), 40 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 | 97.4 | 0.21 | 84.4 | -13.0 |
| 2 | 122.5 | 0.42 | 128.2 | +5.7 |
| 3 | 149.7 | 0.53 | 155.8 | +6.1 |
| 4 | 161.8 | 0.09 | 191.3 | +29.6 |
| 5 | 225.7 | 1.52 | 232.6 | +6.9 |
| 6 | 280.5 | 0.63 | 284.7 | +4.2 |
| 7 | 303.5 | 1.65 | 313.3 | +9.8 |
| 8 | 348.5 | 0.06 | 351.2 | +2.7 |
| 9 | 427.1 | 1.63 | 438.7 | +11.6 |
| 10 | 437.4 | 0.35 | 441.3 | +3.9 |
| 11 | 468.7 | 1.42 | 471.8 | +3.1 |
| 12 | 518.2 | 0.21 | 527.8 | +9.5 |
| 13 | 523.1 | 0.04 | 528.0 | +4.9 |
| 14 | 546.3 | 4.01 | 555.6 | +9.4 |
| 15 | 581.4 | 1.05 | 585.3 | +3.8 |
| 16 | 654.5 | 0.97 | 667.8 | +13.4 |
| 17 | 694.8 | 0.52 | 701.1 | +6.4 |
| 18 | 734.6 | 1.68 | 739.5 | +4.9 |
| 19 | 757.9 | 17.51 | 768.6 | +10.6 |
| 20 | 790.4 | 8.20 | 805.5 | +15.0 |
| 21 | 826.6 | 36.89 | 838.5 | +11.9 |
| 22 | 871.8 | 0.19 | 879.8 | +8.0 |
| 23 | 881.2 | 2.14 | 893.2 | +12.0 |
| 24 | 885.4 | 1.92 | 899.8 | +14.4 |
| 25 | 950.2 | 0.60 | 981.4 | +31.2 |
| 26 | 960.4 | 1.01 | 991.5 | +31.1 |
| 27 | 986.7 | 0.02 | 1017.5 | +30.8 |
| 28 | 1017.3 | 7.37 | 1017.6 | +0.3 |
| 29 | 1054.7 | 2.70 | 1058.7 | +4.0 |
| 30 | 1055.2 | 3.31 | 1062.9 | +7.7 |
| 31 | 1079.9 | 0.27 | 1087.0 | +7.1 |
| 32 | 1085.8 | 0.20 | 1094.7 | +8.9 |
| 33 | 1105.8 | 2.45 | 1114.0 | +8.2 |
| 34 | 1183.4 | 0.88 | 1173.1 | -10.3 |
| 35 | 1194.6 | 0.64 | 1194.5 | -0.1 |
| 36 | 1213.3 | 3.00 | 1215.3 | +2.0 |
| 37 | 1247.3 | 3.03 | 1242.3 | -5.0 |
| 38 | 1263.1 | 2.63 | 1273.4 | +10.2 |
| 39 | 1298.6 | 2.94 | 1307.5 | +8.9 |
| 40 | 1380.3 | 1.92 | 1379.6 | -0.8 |
| 41 | 1410.2 | 0.48 | 1416.7 | +6.5 |
| 42 | 1425.7 | 6.39 | 1428.3 | +2.6 |
| 43 | 1440.7 | 1.51 | 1453.0 | +12.3 |
| 44 | 1447.8 | 1.45 | 1457.5 | +9.7 |
| 45 | 1473.4 | 0.45 | 1488.2 | +14.8 |
| 46 | 1506.7 | 1.27 | 1515.7 | +9.0 |
| 47 | 1512.2 | 10.91 | 1516.2 | +4.0 |
| 48 | 1525.7 | 3.74 | 1537.2 | +11.5 |
| 49 | 1533.3 | 0.00 | 1538.4 | +5.0 |
| 50 | 1540.3 | 6.53 | 1547.2 | +6.9 |
| 51 | 1565.7 | 12.58 | 1593.4 | +27.7 |
| 52 | 1626.4 | 2.56 | 1660.2 | +33.8 |
| 53 | 1658.3 | 7.76 | 1686.3 | +28.0 |
| 54 | 1679.9 | 2.16 | 1725.0 | +45.2 |
| 55 | 3041.5 | 20.07 | 3078.9 | +37.3 |
| 56 | 3043.2 | 37.71 | 3080.1 | +36.9 |
| 57 | 3086.4 | 22.99 | 3138.3 | +51.9 |
| 58 | 3094.1 | 16.19 | 3145.1 | +51.0 |
| 59 | 3123.3 | 19.68 | 3171.2 | +47.9 |
| 60 | 3159.2 | 19.43 | 3206.3 | +47.1 |
| 61 | 3173.1 | 5.80 | 3217.6 | +44.5 |
| 62 | 3176.0 | 3.92 | 3219.4 | +43.4 |
| 63 | 3186.3 | 9.63 | 3229.9 | +43.5 |
| 64 | 3192.8 | 39.70 | 3236.8 | +44.0 |
| 65 | 3202.6 | 34.72 | 3246.1 | +43.4 |
| 66 | 3217.4 | 18.61 | 3261.7 | +44.3 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 22 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, 2026-09-27 15:43:38 → 2026-09-27 16:35:59, 3140 s, peak 4.28 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