naphthalene+CH3+CN C12H9N

B_089a8027aa · SMILES Cc1ccc2c(C#N)cccc2c1 · InChIKey WKKYKNUFFPNPQW-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 2340 cm⁻¹ (4.3 µm), 36 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 — 2026-09-26, ubuntu-32gb-hel1-16
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)

60 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	89.9	0.00	60.2	-29.7
2	94.5	1.39	104.8	+10.3
3	129.1	5.04	146.2	+17.2
4	136.0	2.62	149.6	+13.7
5	204.4	0.14	217.3	+12.9
6	268.9	1.32	275.4	+6.5
7	283.3	0.43	292.1	+8.8
8	386.2	1.34	395.8	+9.6
9	389.9	0.77	407.8	+18.0
10	447.9	0.14	452.0	+4.1
11	454.2	0.92	457.7	+3.5
12	469.8	10.43	482.3	+12.4
13	509.3	2.17	518.7	+9.5
14	555.8	1.34	560.6	+4.8
15	600.9	0.40	613.9	+13.0
16	608.9	0.59	623.0	+14.1
17	652.4	0.01	664.0	+11.6
18	703.7	0.27	709.8	+6.1
19	722.7	1.97	727.6	+4.9
20	767.5	8.66	780.1	+12.6
21	819.0	17.83	834.0	+15.0
22	844.7	32.57	853.3	+8.6
23	846.2	0.91	856.8	+10.7
24	899.1	7.02	917.3	+18.2
25	933.2	0.34	958.6	+25.4
26	948.8	0.65	959.1	+10.3
27	982.3	0.33	1010.8	+28.4
28	984.4	0.95	1017.1	+32.6
29	1036.3	7.07	1037.2	+0.9
30	1043.6	0.33	1051.4	+7.7
31	1077.7	4.72	1084.0	+6.3
32	1104.9	1.46	1113.3	+8.5
33	1194.5	1.27	1192.0	-2.5
34	1200.4	0.71	1195.9	-4.5
35	1210.2	1.84	1208.5	-1.6
36	1253.2	5.64	1246.0	-7.3
37	1271.2	1.59	1280.6	+9.4
38	1304.8	2.97	1311.6	+6.8
39	1385.7	5.93	1376.1	-9.6
40	1409.7	0.15	1418.0	+8.3
41	1416.0	11.99	1422.3	+6.3
42	1444.2	0.09	1453.2	+8.9
43	1475.1	2.45	1488.9	+13.8
44	1509.4	2.41	1513.7	+4.3
45	1512.8	6.16	1521.1	+8.3
46	1525.4	5.10	1537.3	+11.8
47	1559.7	16.67	1589.1	+29.4
48	1628.2	2.93	1663.3	+35.1
49	1648.7	5.43	1677.6	+28.9
50	1687.2	8.78	1730.0	+42.8
51	2339.7	35.81	2380.1	+40.4
52	3043.7	31.30	3078.6	+34.9
53	3095.1	17.64	3145.2	+50.1
54	3129.6	14.84	3176.4	+46.8
55	3177.3	12.49	3221.5	+44.2
56	3183.8	10.86	3226.9	+43.1
57	3187.1	6.68	3230.3	+43.1
58	3207.0	15.37	3249.2	+42.2
59	3209.2	5.04	3251.9	+42.7
60	3221.9	8.82	3263.8	+41.9

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 41 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-hel1-16, 2026-09-26 03:39:29 → 2026-09-26 04:27:38, 2889 s, peak 4.19 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