naphthalene+CHO+OCH3 C12H10O2

B_2d8a02ed8b · SMILES COc1ccc2cccc(C=O)c2c1 · InChIKey WYDUFXRPFJPXGH-UHFFFAOYSA-N

Cheap level done

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)

cheap input (B3LYP) bands

How to read this

45 infrared-active bands (500–3500 cm⁻¹); the strongest at 1317 cm⁻¹ (7.6 µm), 323 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 %).

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-29, ubuntu-32gb-hel1-18
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

Request a run

Not available on this site yet: the pipeline (a molecule in, its spectrum and certificate out) runs on the project's own computer, with three of the four mode families licensed at the DFT stand-in level. Sign-in will be needed only to request runs; reading stays open.

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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	65.9	1.42	89.7	+23.8
2	84.5	0.01	100.3	+15.8
3	110.0	11.55	150.9	+40.9
4	160.7	0.29	167.9	+7.3
5	174.4	1.46	190.2	+15.9
6	200.4	0.21	214.0	+13.6
7	250.5	0.22	264.6	+14.1
8	255.0	6.03	281.9	+26.9
9	325.9	3.80	337.2	+11.3
10	343.7	6.46	351.3	+7.5
11	375.0	0.20	378.3	+3.3
12	430.9	1.67	440.1	+9.2
13	456.9	2.46	462.6	+5.7
14	517.9	3.25	523.0	+5.1
15	523.8	7.07	527.9	+4.0
16	548.3	0.90	560.0	+11.7
17	565.0	12.34	571.5	+6.5
18	666.1	0.87	673.0	+7.0
19	668.5	11.36	679.0	+10.4
20	717.3	7.40	722.7	+5.4
21	761.3	10.77	772.2	+10.9
22	786.5	24.02	794.8	+8.3
23	792.8	0.00	803.5	+10.7
24	843.3	44.24	856.3	+13.0
25	869.1	3.35	878.0	+8.9
26	874.6	27.05	885.5	+10.9
27	921.0	21.09	931.9	+10.9
28	946.0	0.08	966.8	+20.8
29	959.9	0.02	981.5	+21.6
30	986.5	1.22	1016.9	+30.3
31	1022.1	0.01	1044.1	+22.0
32	1040.3	14.60	1050.8	+10.5
33	1083.8	58.56	1099.6	+15.8
34	1117.1	5.08	1125.4	+8.3
35	1183.3	0.70	1176.5	-6.7
36	1190.6	16.54	1188.6	-2.0
37	1195.5	17.89	1199.4	+3.9
38	1212.8	59.05	1220.7	+7.9
39	1227.1	70.92	1226.7	-0.4
40	1261.4	17.95	1264.6	+3.3
41	1294.3	57.14	1302.2	+7.9
42	1316.9	322.88	1329.0	+12.2
43	1367.7	37.73	1358.8	-8.9
44	1402.3	9.38	1407.0	+4.7
45	1426.2	13.15	1426.0	-0.2
46	1461.8	6.92	1469.4	+7.6
47	1490.3	49.94	1498.0	+7.6
48	1495.5	6.31	1511.7	+16.2
49	1515.9	7.42	1530.1	+14.2
50	1523.3	5.72	1536.1	+12.7
51	1534.0	40.81	1543.2	+9.2
52	1568.7	84.42	1595.3	+26.6
53	1619.0	84.18	1655.5	+36.5
54	1648.7	36.77	1676.0	+27.3
55	1684.0	147.59	1726.1	+42.1
56	1780.1	259.47	1813.6	+33.4
57	2963.7	88.49	3016.7	+53.0
58	3028.8	69.62	3064.6	+35.9
59	3089.6	41.73	3137.4	+47.7
60	3160.6	25.12	3203.6	+43.0
61	3180.4	1.72	3224.3	+43.9
62	3186.9	13.34	3230.3	+43.5
63	3204.4	17.00	3247.0	+42.6
64	3219.4	8.22	3262.7	+43.3
65	3230.7	11.97	3275.2	+44.5
66	3235.2	4.08	3280.1	+44.9

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 18 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, 2026-09-29 01:59:18 → 2026-09-29 03:04:27, 3908 s, peak 4.73 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