anthracene+OCH3 C15H12O
A2_0f1a2bd718 · SMILES COc1c2ccccc2cc2ccccc12 · InChIKey DVRKZTKTNYRYLF-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
42 infrared-active bands (500–3500 cm⁻¹); the strongest at 1124 cm⁻¹ (8.9 µm), 132 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)
78 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 | 79.3 | 2.35 | 99.1 | +19.8 |
| 2 | 86.6 | 0.40 | 104.5 | +17.9 |
| 3 | 118.9 | 1.39 | 131.7 | +12.8 |
| 4 | 135.1 | 0.31 | 139.0 | +3.9 |
| 5 | 164.7 | 0.08 | 191.1 | +26.5 |
| 6 | 226.1 | 0.64 | 229.8 | +3.7 |
| 7 | 238.6 | 0.02 | 252.4 | +13.8 |
| 8 | 253.4 | 4.05 | 260.6 | +7.3 |
| 9 | 305.5 | 4.78 | 314.8 | +9.3 |
| 10 | 347.7 | 1.94 | 356.8 | +9.1 |
| 11 | 398.7 | 0.13 | 401.1 | +2.4 |
| 12 | 429.5 | 0.16 | 435.5 | +5.9 |
| 13 | 433.5 | 5.14 | 439.5 | +6.0 |
| 14 | 488.3 | 0.05 | 492.1 | +3.8 |
| 15 | 507.3 | 0.00 | 518.7 | +11.4 |
| 16 | 528.8 | 2.22 | 535.8 | +7.0 |
| 17 | 575.7 | 3.12 | 585.5 | +9.8 |
| 18 | 581.1 | 0.03 | 588.2 | +7.1 |
| 19 | 626.8 | 8.57 | 628.8 | +2.0 |
| 20 | 654.6 | 1.92 | 658.5 | +3.9 |
| 21 | 671.6 | 12.94 | 684.0 | +12.4 |
| 22 | 708.6 | 3.12 | 714.8 | +6.2 |
| 23 | 755.2 | 50.44 | 759.8 | +4.6 |
| 24 | 755.9 | 0.17 | 768.7 | +12.8 |
| 25 | 777.5 | 0.00 | 784.7 | +7.2 |
| 26 | 808.0 | 6.99 | 823.3 | +15.3 |
| 27 | 863.5 | 22.78 | 876.5 | +13.0 |
| 28 | 873.9 | 0.17 | 876.8 | +2.9 |
| 29 | 875.0 | 0.22 | 884.1 | +9.1 |
| 30 | 875.7 | 0.34 | 886.4 | +10.7 |
| 31 | 895.3 | 18.27 | 915.2 | +19.9 |
| 32 | 943.5 | 1.02 | 948.4 | +4.9 |
| 33 | 964.0 | 0.00 | 993.0 | +29.1 |
| 34 | 966.6 | 2.97 | 995.8 | +29.2 |
| 35 | 992.8 | 0.02 | 1017.9 | +25.1 |
| 36 | 993.6 | 0.48 | 1019.3 | +25.7 |
| 37 | 1001.8 | 25.42 | 1021.3 | +19.5 |
| 38 | 1041.8 | 0.43 | 1050.8 | +9.1 |
| 39 | 1042.2 | 5.37 | 1052.8 | +10.6 |
| 40 | 1124.4 | 131.85 | 1129.1 | +4.7 |
| 41 | 1135.0 | 0.56 | 1143.3 | +8.4 |
| 42 | 1177.6 | 0.09 | 1151.2 | -26.5 |
| 43 | 1183.8 | 1.19 | 1191.7 | +7.9 |
| 44 | 1193.6 | 3.91 | 1195.7 | +2.1 |
| 45 | 1199.4 | 3.45 | 1201.0 | +1.6 |
| 46 | 1211.7 | 0.23 | 1209.5 | -2.3 |
| 47 | 1224.6 | 18.41 | 1234.7 | +10.1 |
| 48 | 1256.5 | 1.57 | 1255.2 | -1.3 |
| 49 | 1295.5 | 2.30 | 1303.1 | +7.6 |
| 50 | 1316.6 | 20.48 | 1326.0 | +9.3 |
| 51 | 1368.8 | 2.21 | 1330.0 | -38.8 |
| 52 | 1377.9 | 128.07 | 1400.8 | +22.8 |
| 53 | 1421.9 | 6.55 | 1429.3 | +7.4 |
| 54 | 1425.7 | 0.14 | 1438.6 | +12.9 |
| 55 | 1446.7 | 25.94 | 1466.6 | +19.9 |
| 56 | 1492.3 | 6.85 | 1500.2 | +7.9 |
| 57 | 1496.8 | 0.02 | 1509.7 | +12.9 |
| 58 | 1505.1 | 2.94 | 1519.0 | +13.9 |
| 59 | 1516.3 | 4.74 | 1526.1 | +9.8 |
| 60 | 1531.3 | 8.64 | 1541.4 | +10.0 |
| 61 | 1535.9 | 0.00 | 1555.1 | +19.2 |
| 62 | 1585.6 | 0.25 | 1617.4 | +31.9 |
| 63 | 1610.1 | 8.93 | 1642.0 | +31.9 |
| 64 | 1631.1 | 4.63 | 1656.8 | +25.7 |
| 65 | 1679.0 | 1.90 | 1719.8 | +40.8 |
| 66 | 1685.1 | 10.35 | 1729.8 | +44.7 |
| 67 | 3032.7 | 52.53 | 3067.3 | +34.7 |
| 68 | 3094.6 | 26.96 | 3142.4 | +47.8 |
| 69 | 3149.3 | 35.00 | 3193.6 | +44.4 |
| 70 | 3176.5 | 1.09 | 3221.4 | +44.8 |
| 71 | 3178.9 | 0.01 | 3222.4 | +43.5 |
| 72 | 3181.1 | 5.63 | 3224.0 | +42.9 |
| 73 | 3190.2 | 2.23 | 3233.4 | +43.2 |
| 74 | 3190.7 | 36.21 | 3233.8 | +43.1 |
| 75 | 3204.5 | 24.35 | 3247.5 | +43.1 |
| 76 | 3204.7 | 46.95 | 3247.7 | +42.9 |
| 77 | 3222.9 | 21.40 | 3266.7 | +43.8 |
| 78 | 3223.6 | 10.09 | 3267.2 | +43.7 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 29 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-hel1-10, 2026-09-20 03:35:57 → 2026-09-20 05:21:52, 6355 s, peak 6.45 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