naphthalene+CH3+SH C11H10S

B_00a6eb272d · SMILES Cc1cccc2cc(S)ccc12 · InChIKey MOIPGONMGBCQEP-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 1653 cm⁻¹ (6.0 µm), 39 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-hel1-14
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	88.9	0.07	98.2	+9.4
2	140.3	9.18	158.1	+17.7
3	148.0	12.56	199.6	+51.6
4	180.9	0.66	222.1	+41.2
5	189.2	0.88	239.3	+50.0
6	246.8	1.61	255.3	+8.5
7	273.0	0.01	284.4	+11.4
8	293.9	0.44	300.1	+6.1
9	373.9	2.02	380.8	+6.9
10	421.3	4.25	430.1	+8.8
11	459.0	2.22	466.3	+7.3
12	491.7	2.89	496.4	+4.6
13	510.1	1.81	522.2	+12.1
14	561.2	0.51	569.4	+8.2
15	579.0	2.67	583.7	+4.7
16	625.1	4.18	632.2	+7.1
17	640.7	0.46	657.8	+17.1
18	726.0	0.24	732.8	+6.8
19	765.5	3.37	774.6	+9.2
20	798.1	14.75	811.0	+12.8
21	830.8	33.28	841.3	+10.5
22	833.1	8.30	847.2	+14.2
23	874.7	16.07	890.6	+15.9
24	902.5	14.42	916.1	+13.6
25	908.7	1.22	926.9	+18.2
26	945.6	13.44	976.5	+30.9
27	963.8	0.03	992.5	+28.7
28	973.5	0.92	1007.4	+33.9
29	1001.9	5.95	1012.7	+10.8
30	1076.6	0.16	1081.0	+4.4
31	1077.4	2.21	1087.9	+10.5
32	1109.3	1.45	1114.1	+4.8
33	1129.2	37.65	1145.0	+15.8
34	1196.7	2.09	1190.9	-5.8
35	1205.0	3.03	1205.7	+0.7
36	1238.0	10.26	1228.5	-9.5
37	1275.5	0.06	1284.6	+9.1
38	1303.0	2.24	1309.3	+6.3
39	1391.6	3.47	1382.4	-9.2
40	1402.5	4.54	1409.3	+6.8
41	1414.4	0.35	1423.7	+9.3
42	1444.2	0.94	1458.6	+14.4
43	1473.8	16.37	1485.3	+11.5
44	1504.3	3.75	1521.5	+17.2
45	1515.3	6.73	1522.9	+7.6
46	1532.0	1.70	1543.1	+11.2
47	1551.7	22.57	1581.8	+30.0
48	1630.3	2.18	1663.1	+32.7
49	1653.1	38.90	1681.8	+28.7
50	1674.2	22.59	1720.7	+46.5
51	2694.1	11.79	2738.7	+44.6
52	3039.5	28.17	3076.3	+36.8
53	3089.4	19.85	3140.9	+51.5
54	3128.1	18.40	3175.7	+47.6
55	3176.9	4.04	3221.0	+44.1
56	3179.8	2.60	3224.1	+44.3
57	3185.3	29.12	3229.0	+43.7
58	3191.5	3.91	3235.5	+44.0
59	3203.4	34.90	3246.6	+43.2
60	3214.6	12.98	3258.8	+44.1

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 23 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-hel1-14, 2026-09-27 06:44:34 → 2026-09-27 07:41:02, 3388 s, peak 4.17 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