naphthalene+Cl+CONH2 C11H8ClNO

B_0915d41755 · SMILES NC(=O)c1ccc2c(Cl)cccc2c1 · InChIKey YAQXVVLKANZKKN-UHFFFAOYSA-N

Cheap level done analytic check agrees

Infrared spectrum at the cheap level (B3LYP/6-31G*, the pipeline's input)

cheap input (B3LYP) bands

How to read this

41 infrared-active bands (500–3500 cm⁻¹); the strongest at 1787 cm⁻¹ (5.6 µm), 282 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

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.

Notify me when this molecule climbs the ladder: open a GitHub issue — you are subscribed to it and we close it with a link when the page changes. No e-mail address is stored by this site.

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	57.7	5.60	81.4	+23.7
2	75.8	2.05	95.9	+20.1
3	131.8	1.77	147.4	+15.7
4	144.9	1.62	154.2	+9.3
5	220.0	6.60	226.8	+6.7
6	235.3	2.51	251.2	+15.9
7	243.6	0.43	253.4	+9.7
8	339.3	4.29	345.3	+6.0
9	392.6	1.93	397.4	+4.8
10	410.5	2.81	417.1	+6.6
11	420.2	9.84	432.4	+12.2
12	425.0	155.72	445.0	+20.0
13	473.9	21.03	488.9	+15.0
14	519.9	3.64	529.6	+9.7
15	550.5	0.62	555.9	+5.4
16	555.7	24.82	569.7	+14.0
17	571.2	30.60	589.8	+18.6
18	589.8	17.87	599.0	+9.1
19	641.0	12.31	657.2	+16.2
20	675.6	1.46	684.6	+9.0
21	707.3	27.41	714.9	+7.6
22	749.1	6.08	762.2	+13.1
23	786.3	50.19	802.2	+15.9
24	806.3	23.58	823.5	+17.2
25	824.2	9.73	832.9	+8.7
26	865.0	12.61	879.9	+14.9
27	899.2	9.64	921.0	+21.8
28	911.2	11.69	926.1	+14.9
29	927.2	4.40	949.8	+22.6
30	976.5	1.62	995.3	+18.9
31	983.8	41.54	1009.5	+25.7
32	997.1	0.39	1025.6	+28.5
33	1094.9	10.60	1099.1	+4.2
34	1101.0	6.99	1115.5	+14.5
35	1137.3	8.68	1148.9	+11.7
36	1178.3	1.66	1171.4	-6.9
37	1189.9	3.23	1192.0	+2.1
38	1230.9	20.85	1223.7	-7.2
39	1241.6	9.13	1240.6	-0.9
40	1296.0	15.54	1300.0	+4.0
41	1367.3	112.27	1363.8	-3.5
42	1386.2	171.33	1400.9	+14.7
43	1401.6	4.40	1407.0	+5.4
44	1411.0	13.02	1420.1	+9.1
45	1464.3	6.05	1480.7	+16.3
46	1509.1	10.21	1524.6	+15.6
47	1548.8	7.84	1579.8	+31.0
48	1616.9	17.81	1650.4	+33.5
49	1645.9	158.73	1663.4	+17.5
50	1653.1	7.76	1681.3	+28.2
51	1679.8	5.04	1727.2	+47.5
52	1787.3	281.62	1820.0	+32.6
53	3187.1	0.40	3231.5	+44.4
54	3190.4	10.78	3234.4	+44.0
55	3207.8	18.65	3250.3	+42.5
56	3222.9	0.54	3266.6	+43.7
57	3226.2	5.16	3268.4	+42.2
58	3236.5	2.79	3280.6	+44.1
59	3576.8	39.42	3625.3	+48.5
60	3695.1	26.06	3744.1	+48.9

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 3 cm⁻¹; wb97x max |Δω| 4 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 16:35:59 → 2026-09-27 17:37:48, 3708 s, peak 4.55 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