anthracene+CH3 C15H12
A2_1d6c152813 · SMILES Cc1ccc2cc3ccccc3cc2c1 · InChIKey GYMFBYTZOGMSQJ-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 3038 cm⁻¹ (3.3 µm), 48 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)
75 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 | 71.5 | 0.86 | 83.3 | +11.7 |
| 2 | 111.6 | 0.12 | 124.3 | +12.7 |
| 3 | 118.0 | 0.00 | 166.6 | +48.6 |
| 4 | 187.6 | 0.05 | 194.7 | +7.1 |
| 5 | 192.5 | 0.94 | 198.5 | +6.0 |
| 6 | 254.9 | 0.07 | 268.7 | +13.8 |
| 7 | 314.9 | 0.84 | 320.5 | +5.6 |
| 8 | 323.2 | 0.95 | 331.0 | +7.8 |
| 9 | 372.3 | 0.04 | 375.2 | +2.9 |
| 10 | 394.0 | 0.51 | 404.4 | +10.4 |
| 11 | 426.8 | 0.51 | 434.1 | +7.3 |
| 12 | 484.5 | 10.83 | 487.4 | +2.9 |
| 13 | 488.6 | 0.02 | 492.9 | +4.3 |
| 14 | 510.2 | 0.25 | 515.0 | +4.8 |
| 15 | 532.8 | 0.73 | 545.9 | +13.1 |
| 16 | 591.1 | 3.69 | 594.8 | +3.8 |
| 17 | 605.8 | 1.92 | 621.4 | +15.6 |
| 18 | 636.0 | 2.82 | 639.5 | +3.5 |
| 19 | 662.1 | 1.40 | 665.1 | +3.0 |
| 20 | 756.2 | 18.28 | 763.7 | +7.5 |
| 21 | 757.5 | 17.82 | 769.2 | +11.8 |
| 22 | 768.2 | 0.03 | 774.9 | +6.6 |
| 23 | 778.0 | 0.15 | 785.6 | +7.7 |
| 24 | 780.9 | 0.03 | 792.2 | +11.2 |
| 25 | 814.8 | 2.13 | 828.4 | +13.6 |
| 26 | 846.8 | 0.27 | 853.8 | +7.0 |
| 27 | 855.9 | 0.31 | 866.7 | +10.9 |
| 28 | 878.4 | 12.74 | 894.1 | +15.7 |
| 29 | 902.6 | 39.09 | 921.1 | +18.5 |
| 30 | 921.0 | 4.59 | 928.9 | +7.9 |
| 31 | 921.5 | 1.24 | 939.6 | +18.1 |
| 32 | 958.4 | 3.31 | 974.9 | +16.5 |
| 33 | 965.7 | 0.73 | 989.7 | +24.0 |
| 34 | 969.6 | 0.77 | 1003.9 | +34.3 |
| 35 | 988.5 | 0.00 | 1018.6 | +30.1 |
| 36 | 1037.3 | 0.11 | 1042.0 | +4.6 |
| 37 | 1041.5 | 10.11 | 1050.8 | +9.4 |
| 38 | 1077.0 | 4.32 | 1087.8 | +10.8 |
| 39 | 1144.2 | 0.30 | 1132.3 | -11.9 |
| 40 | 1178.7 | 2.68 | 1159.3 | -19.4 |
| 41 | 1189.4 | 1.89 | 1195.2 | +5.9 |
| 42 | 1200.3 | 0.99 | 1206.0 | +5.7 |
| 43 | 1205.0 | 2.63 | 1217.9 | +12.9 |
| 44 | 1224.5 | 0.06 | 1231.7 | +7.2 |
| 45 | 1298.7 | 6.89 | 1307.2 | +8.5 |
| 46 | 1306.3 | 0.03 | 1312.5 | +6.3 |
| 47 | 1307.7 | 0.34 | 1316.4 | +8.7 |
| 48 | 1342.0 | 3.12 | 1345.4 | +3.4 |
| 49 | 1388.6 | 4.48 | 1363.6 | -24.9 |
| 50 | 1407.7 | 1.17 | 1415.0 | +7.3 |
| 51 | 1434.5 | 0.06 | 1449.5 | +15.0 |
| 52 | 1442.7 | 2.58 | 1455.3 | +12.6 |
| 53 | 1450.8 | 0.64 | 1470.6 | +19.8 |
| 54 | 1479.8 | 0.39 | 1497.6 | +17.8 |
| 55 | 1510.3 | 4.52 | 1518.4 | +8.1 |
| 56 | 1512.0 | 5.72 | 1525.3 | +13.3 |
| 57 | 1521.5 | 6.41 | 1536.1 | +14.6 |
| 58 | 1536.7 | 1.62 | 1559.0 | +22.3 |
| 59 | 1594.0 | 3.74 | 1623.8 | +29.8 |
| 60 | 1610.0 | 0.14 | 1640.3 | +30.3 |
| 61 | 1644.8 | 1.02 | 1671.3 | +26.5 |
| 62 | 1684.7 | 2.66 | 1727.8 | +43.1 |
| 63 | 1695.1 | 18.53 | 1740.3 | +45.2 |
| 64 | 3037.8 | 47.69 | 3073.5 | +35.7 |
| 65 | 3086.6 | 21.76 | 3137.5 | +51.0 |
| 66 | 3126.2 | 15.92 | 3173.2 | +47.0 |
| 67 | 3170.3 | 1.94 | 3215.8 | +45.5 |
| 68 | 3171.3 | 6.41 | 3216.2 | +44.9 |
| 69 | 3173.4 | 17.68 | 3217.3 | +44.0 |
| 70 | 3174.4 | 10.77 | 3218.8 | +44.4 |
| 71 | 3176.6 | 13.98 | 3219.9 | +43.3 |
| 72 | 3181.3 | 0.17 | 3224.7 | +43.4 |
| 73 | 3191.2 | 37.98 | 3234.6 | +43.4 |
| 74 | 3194.6 | 36.22 | 3237.8 | +43.2 |
| 75 | 3207.8 | 40.11 | 3250.5 | +42.8 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 28 cm⁻¹.
Provenance
- Releases: layerA2_2026-09-23, layerA2_2026-09-23b, layerA2_2026-09-24
- Entered the corpus as: substituted three- and four-ring cores, enumerated from the parents (layer A′) (layer A2)
- Run: ubuntu-32gb-hel1-11, 2026-09-21 11:01:19 → 2026-09-21 12:38:03, 5803 s, peak 5.98 GB, deck 97ed2d67c66b
- 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