naphthalene+ethynyl+SH C12H8S

B_1e03da0643 · SMILES C#Cc1cccc2c(S)cccc12 · InChIKey OQEYACKWQHXAKV-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

39 infrared-active bands (500–3500 cm⁻¹); the strongest at 3494 cm⁻¹ (2.9 µm), 89 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 — 2026-09-28, 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)

57 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	65.4	0.09	74.0	+8.7
2	136.1	0.06	148.0	+11.9
3	158.6	0.62	171.6	+13.0
4	172.4	2.29	194.7	+22.3
5	194.5	16.46	226.9	+32.5
6	230.8	3.33	240.8	+10.0
7	243.0	2.39	296.3	+53.3
8	366.6	1.93	374.9	+8.3
9	383.0	0.79	396.6	+13.6
10	398.0	1.75	406.8	+8.8
11	463.6	2.87	468.6	+5.1
12	478.2	0.11	489.9	+11.7
13	506.9	2.83	515.5	+8.5
14	518.3	1.39	528.0	+9.7
15	559.3	38.66	575.6	+16.3
16	568.2	2.40	606.8	+38.6
17	595.7	7.13	622.2	+26.4
18	613.4	0.21	625.1	+11.7
19	636.2	41.36	676.6	+40.4
20	670.7	1.31	684.6	+13.9
21	751.9	0.14	760.8	+8.9
22	788.4	14.56	795.0	+6.6
23	812.5	72.57	824.8	+12.3
24	817.9	3.52	828.0	+10.1
25	834.4	0.39	853.7	+19.3
26	869.3	2.63	878.0	+8.6
27	919.9	4.85	943.8	+23.9
28	926.7	0.64	952.0	+25.3
29	944.1	7.63	973.0	+28.9
30	983.1	0.40	1013.1	+30.0
31	988.6	0.54	1017.5	+28.9
32	1072.7	3.69	1081.2	+8.6
33	1094.1	1.63	1102.7	+8.6
34	1121.5	2.68	1133.4	+11.9
35	1191.7	2.55	1185.5	-6.2
36	1207.5	0.97	1205.3	-2.2
37	1236.5	3.11	1235.8	-0.8
38	1248.3	5.05	1247.3	-1.1
39	1273.2	6.11	1286.3	+13.1
40	1359.0	5.61	1347.8	-11.2
41	1394.1	0.78	1402.7	+8.6
42	1436.9	11.82	1445.8	+8.9
43	1443.1	13.73	1455.0	+11.9
44	1503.5	0.03	1520.9	+17.4
45	1551.5	11.23	1582.7	+31.2
46	1622.3	3.12	1659.9	+37.6
47	1639.4	11.33	1666.1	+26.7
48	1662.0	0.80	1705.1	+43.1
49	2218.2	1.54	2257.6	+39.4
50	2652.3	21.47	2701.3	+48.9
51	3195.0	11.46	3237.8	+42.8
52	3196.0	4.64	3238.8	+42.8
53	3213.6	3.72	3256.7	+43.1
54	3216.1	11.20	3258.8	+42.7
55	3222.1	10.02	3265.5	+43.3
56	3226.5	8.75	3271.6	+45.0
57	3493.8	89.33	3528.3	+34.4

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 19 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, 2026-09-28 06:47:28 → 2026-09-28 07:37:58, 3029 s, peak 4.22 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