naphthalene+CH3+NO2 C11H9NO2

B_094bb73460 · SMILES Cc1cccc2cc([N+](=O)[O-])ccc12 · InChIKey SOXBGESONWKYDX-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

37 infrared-active bands (500–3500 cm⁻¹); the strongest at 1394 cm⁻¹ (7.2 µm), 446 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 — 2026-09-27, ubuntu-32gb-hel1-18
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

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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)

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	57.0	0.00	93.3	+36.2
2	82.7	0.79	123.5	+40.9
3	147.5	0.05	159.7	+12.2
4	178.6	0.88	194.1	+15.4
5	181.4	0.23	222.6	+41.2
6	249.2	5.78	258.6	+9.4
7	259.4	0.64	271.6	+12.2
8	279.1	0.55	286.7	+7.6
9	356.6	0.82	365.8	+9.3
10	425.9	2.23	432.0	+6.2
11	438.4	0.09	446.9	+8.5
12	490.3	1.08	494.9	+4.6
13	494.2	0.03	507.2	+12.9
14	551.3	4.59	559.6	+8.3
15	557.4	3.20	563.9	+6.5
16	578.5	3.54	582.8	+4.4
17	621.4	3.13	629.2	+7.9
18	627.2	0.18	641.9	+14.7
19	725.3	0.38	732.4	+7.1
20	742.1	6.82	756.7	+14.6
21	778.7	16.41	791.2	+12.5
22	805.3	29.62	817.6	+12.4
23	807.2	32.38	818.2	+11.0
24	852.3	12.77	864.9	+12.6
25	854.0	10.17	865.0	+10.9
26	914.6	4.90	928.9	+14.2
27	945.1	12.04	959.2	+14.1
28	947.6	8.80	961.0	+13.4
29	983.2	0.45	1009.9	+26.7
30	985.9	1.85	1014.5	+28.6
31	1004.4	1.49	1015.0	+10.6
32	1078.5	3.06	1083.9	+5.4
33	1078.9	12.71	1089.3	+10.4
34	1110.0	4.78	1114.2	+4.2
35	1124.6	44.62	1138.7	+14.1
36	1181.9	3.33	1183.0	+1.1
37	1201.2	0.70	1196.4	-4.8
38	1244.5	0.40	1235.8	-8.7
39	1274.5	0.39	1280.8	+6.3
40	1295.6	9.16	1302.9	+7.3
41	1381.8	16.54	1375.8	-6.0
42	1394.3	446.40	1421.9	+27.7
43	1414.8	3.03	1423.2	+8.4
44	1424.2	3.16	1442.0	+17.8
45	1445.8	1.07	1460.1	+14.3
46	1473.2	3.85	1485.3	+12.2
47	1504.8	1.57	1522.6	+17.8
48	1515.4	7.46	1522.9	+7.5
49	1531.2	11.09	1542.3	+11.1
50	1560.0	9.56	1589.7	+29.6
51	1622.2	113.04	1648.9	+26.6
52	1646.1	2.98	1678.1	+32.1
53	1664.5	60.56	1692.7	+28.2
54	1679.3	38.32	1723.0	+43.8
55	3043.2	23.12	3079.1	+35.9
56	3094.0	16.77	3144.7	+50.7
57	3132.2	15.26	3179.3	+47.1
58	3183.9	7.75	3227.0	+43.1
59	3192.8	11.88	3235.7	+42.8
60	3210.4	24.70	3252.9	+42.5
61	3219.1	6.14	3262.8	+43.6
62	3239.1	0.82	3282.3	+43.2
63	3255.2	2.13	3298.0	+42.8

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 30 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, 2026-09-27 17:37:48 → 2026-09-27 18:40:34, 3766 s, peak 4.67 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