biphenyl+CH3 C13H12
B_1e9434eced · SMILES Cc1ccccc1-c1ccccc1 · InChIKey ALLIZEAXNXSFGD-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 3207 cm⁻¹ (3.1 µm), 41 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)
69 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 | -35.6 | 0.00 | -38.1 | -2.6 |
| 2 | 86.7 | 0.17 | 45.3 | -41.4 |
| 3 | 88.7 | 0.01 | 99.4 | +10.7 |
| 4 | 99.9 | 0.39 | 107.4 | +7.6 |
| 5 | 193.8 | 0.73 | 196.2 | +2.4 |
| 6 | 256.1 | 0.40 | 259.1 | +3.0 |
| 7 | 296.1 | 0.17 | 300.4 | +4.3 |
| 8 | 327.0 | 1.05 | 333.6 | +6.6 |
| 9 | 402.0 | 0.66 | 405.8 | +3.8 |
| 10 | 414.2 | 0.00 | 424.9 | +10.7 |
| 11 | 465.0 | 2.91 | 476.9 | +11.9 |
| 12 | 530.7 | 4.06 | 537.1 | +6.4 |
| 13 | 563.9 | 1.10 | 574.6 | +10.7 |
| 14 | 574.0 | 3.04 | 581.1 | +7.1 |
| 15 | 634.2 | 4.71 | 637.9 | +3.7 |
| 16 | 634.8 | 0.13 | 638.1 | +3.3 |
| 17 | 717.8 | 25.74 | 727.6 | +9.8 |
| 18 | 733.1 | 0.48 | 740.1 | +7.0 |
| 19 | 744.9 | 11.09 | 759.4 | +14.5 |
| 20 | 776.4 | 26.84 | 790.9 | +14.5 |
| 21 | 780.0 | 22.19 | 796.2 | +16.3 |
| 22 | 819.3 | 0.37 | 827.5 | +8.2 |
| 23 | 863.1 | 0.02 | 880.7 | +17.5 |
| 24 | 884.5 | 0.04 | 907.5 | +23.0 |
| 25 | 930.0 | 1.48 | 951.8 | +21.8 |
| 26 | 945.3 | 0.56 | 978.0 | +32.7 |
| 27 | 967.4 | 0.01 | 999.3 | +32.0 |
| 28 | 983.5 | 0.00 | 1012.8 | +29.3 |
| 29 | 995.2 | 0.10 | 1019.0 | +23.8 |
| 30 | 1017.9 | 0.41 | 1023.4 | +5.5 |
| 31 | 1018.5 | 4.98 | 1025.1 | +6.6 |
| 32 | 1027.1 | 8.87 | 1036.9 | +9.8 |
| 33 | 1064.9 | 0.19 | 1072.2 | +7.2 |
| 34 | 1074.7 | 2.44 | 1076.8 | +2.1 |
| 35 | 1080.6 | 1.95 | 1092.2 | +11.6 |
| 36 | 1107.4 | 3.67 | 1113.3 | +6.0 |
| 37 | 1150.3 | 2.10 | 1158.1 | +7.8 |
| 38 | 1192.4 | 0.01 | 1183.6 | -8.9 |
| 39 | 1195.5 | 0.33 | 1190.6 | -4.9 |
| 40 | 1212.3 | 0.53 | 1210.3 | -2.1 |
| 41 | 1226.8 | 0.33 | 1241.3 | +14.5 |
| 42 | 1300.7 | 1.48 | 1299.4 | -1.3 |
| 43 | 1318.1 | 0.93 | 1299.9 | -18.2 |
| 44 | 1328.0 | 0.17 | 1316.3 | -11.6 |
| 45 | 1338.8 | 0.30 | 1337.6 | -1.3 |
| 46 | 1361.7 | 0.17 | 1356.5 | -5.3 |
| 47 | 1446.0 | 0.83 | 1451.5 | +5.6 |
| 48 | 1486.9 | 1.75 | 1498.5 | +11.6 |
| 49 | 1487.4 | 3.15 | 1498.5 | +11.2 |
| 50 | 1512.6 | 9.94 | 1512.7 | +0.1 |
| 51 | 1519.9 | 10.96 | 1528.3 | +8.4 |
| 52 | 1533.9 | 26.90 | 1544.9 | +11.0 |
| 53 | 1550.8 | 0.94 | 1572.1 | +21.2 |
| 54 | 1630.2 | 0.14 | 1665.2 | +35.0 |
| 55 | 1634.5 | 1.27 | 1668.0 | +33.5 |
| 56 | 1659.8 | 4.69 | 1694.9 | +35.1 |
| 57 | 1664.9 | 2.16 | 1705.9 | +41.0 |
| 58 | 3049.2 | 23.41 | 3084.3 | +35.1 |
| 59 | 3102.5 | 13.12 | 3152.6 | +50.1 |
| 60 | 3126.6 | 25.57 | 3174.2 | +47.6 |
| 61 | 3174.0 | 8.71 | 3217.8 | +43.8 |
| 62 | 3177.7 | 2.87 | 3220.9 | +43.2 |
| 63 | 3183.3 | 3.48 | 3226.7 | +43.5 |
| 64 | 3183.3 | 1.00 | 3227.1 | +43.8 |
| 65 | 3192.6 | 18.71 | 3235.7 | +43.1 |
| 66 | 3193.9 | 29.96 | 3237.3 | +43.4 |
| 67 | 3198.9 | 39.62 | 3242.0 | +43.2 |
| 68 | 3206.8 | 40.78 | 3249.7 | +42.9 |
| 69 | 3208.5 | 11.19 | 3251.3 | +42.8 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 3 cm⁻¹; wb97x max |Δω| 68 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 13:44:17 → 2026-09-28 14:46:13, 3715 s, peak 4.75 GB, deck 9e27bf8e9348
- Imaginary modes: B3LYP 1, ωB97X 1
- Cheap-level band heights: dipole derivatives dipole_b3lyp_cphf.npz, Hessian hessian_b3lyp.npz
- Source files: corpus factory · manifest