naphthalene+CH3+ethynyl C13H10
B_62df344e7f · SMILES C#Cc1ccc2cc(C)ccc2c1 · InChIKey YITZNAZYMBCXNG-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
45 infrared-active bands (500–3500 cm⁻¹); the strongest at 3495 cm⁻¹ (2.9 µm), 97 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)
63 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 | 67.8 | 0.47 | 47.8 | -20.0 |
| 2 | 95.5 | 0.11 | 86.6 | -9.0 |
| 3 | 125.9 | 0.46 | 141.8 | +15.9 |
| 4 | 166.7 | 0.00 | 181.3 | +14.6 |
| 5 | 183.8 | 0.46 | 189.9 | +6.1 |
| 6 | 261.6 | 0.06 | 268.9 | +7.3 |
| 7 | 294.1 | 2.06 | 308.7 | +14.7 |
| 8 | 368.2 | 0.08 | 373.4 | +5.3 |
| 9 | 400.7 | 0.02 | 414.9 | +14.3 |
| 10 | 408.8 | 0.86 | 415.8 | +7.0 |
| 11 | 455.3 | 0.60 | 470.0 | +14.8 |
| 12 | 491.8 | 7.81 | 501.7 | +9.9 |
| 13 | 524.2 | 0.92 | 529.5 | +5.3 |
| 14 | 548.0 | 36.33 | 567.4 | +19.4 |
| 15 | 556.2 | 1.82 | 568.8 | +12.6 |
| 16 | 564.4 | 1.37 | 585.8 | +21.4 |
| 17 | 581.9 | 12.12 | 635.4 | +53.6 |
| 18 | 626.7 | 43.14 | 672.5 | +45.9 |
| 19 | 671.4 | 0.73 | 684.5 | +13.1 |
| 20 | 681.3 | 0.73 | 686.1 | +4.8 |
| 21 | 761.4 | 0.64 | 768.9 | +7.5 |
| 22 | 777.0 | 0.01 | 794.6 | +17.6 |
| 23 | 818.9 | 2.33 | 830.5 | +11.6 |
| 24 | 835.4 | 28.45 | 846.9 | +11.4 |
| 25 | 836.7 | 0.37 | 849.4 | +12.7 |
| 26 | 904.7 | 19.93 | 924.7 | +20.0 |
| 27 | 911.4 | 13.66 | 939.0 | +27.6 |
| 28 | 940.5 | 2.81 | 948.7 | +8.2 |
| 29 | 969.0 | 0.60 | 994.9 | +25.9 |
| 30 | 970.3 | 0.25 | 997.6 | +27.3 |
| 31 | 985.0 | 1.12 | 999.9 | +14.9 |
| 32 | 1036.2 | 8.04 | 1039.4 | +3.2 |
| 33 | 1076.5 | 4.52 | 1084.8 | +8.4 |
| 34 | 1160.0 | 0.73 | 1160.1 | +0.1 |
| 35 | 1179.5 | 0.83 | 1187.8 | +8.3 |
| 36 | 1197.4 | 2.68 | 1188.5 | -9.0 |
| 37 | 1207.8 | 0.99 | 1215.9 | +8.1 |
| 38 | 1252.6 | 4.44 | 1246.2 | -6.4 |
| 39 | 1292.5 | 0.42 | 1300.7 | +8.2 |
| 40 | 1301.9 | 5.32 | 1311.2 | +9.2 |
| 41 | 1376.1 | 1.00 | 1384.4 | +8.3 |
| 42 | 1414.6 | 0.53 | 1409.5 | -5.2 |
| 43 | 1423.3 | 6.98 | 1424.8 | +1.4 |
| 44 | 1443.3 | 0.59 | 1454.1 | +10.8 |
| 45 | 1447.1 | 0.23 | 1467.2 | +20.1 |
| 46 | 1512.8 | 5.80 | 1518.4 | +5.6 |
| 47 | 1518.8 | 5.70 | 1524.9 | +6.2 |
| 48 | 1529.0 | 0.38 | 1547.9 | +19.0 |
| 49 | 1549.9 | 11.18 | 1575.4 | +25.5 |
| 50 | 1616.6 | 0.49 | 1648.0 | +31.5 |
| 51 | 1661.1 | 13.03 | 1692.5 | +31.5 |
| 52 | 1688.1 | 10.60 | 1736.0 | +47.9 |
| 53 | 2223.2 | 6.01 | 2261.4 | +38.2 |
| 54 | 3040.4 | 41.42 | 3075.7 | +35.4 |
| 55 | 3090.5 | 20.27 | 3141.2 | +50.7 |
| 56 | 3127.3 | 15.90 | 3174.3 | +47.0 |
| 57 | 3173.1 | 14.89 | 3217.8 | +44.7 |
| 58 | 3174.5 | 8.38 | 3218.2 | +43.7 |
| 59 | 3183.8 | 15.42 | 3227.1 | +43.3 |
| 60 | 3192.7 | 21.45 | 3236.4 | +43.7 |
| 61 | 3199.8 | 11.16 | 3243.0 | +43.3 |
| 62 | 3214.7 | 11.77 | 3257.5 | +42.8 |
| 63 | 3495.2 | 97.45 | 3529.9 | +34.7 |
Second route
Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 39 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, 2026-09-30 10:29:13 → 2026-09-30 11:20:24, 3071 s, peak 4.2 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