naphthalene+ethynyl+SH C12H8S

B_095a0abff0 · SMILES C#Cc1ccc2ccccc2c1S · InChIKey RWXCAKBJTOQNOS-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

38 infrared-active bands (500–3500 cm⁻¹); the strongest at 3492 cm⁻¹ (2.9 µm), 103 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-hel1-18
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)

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	72.8	0.50	83.3	+10.5
2	110.3	0.06	118.0	+7.8
3	143.2	0.23	159.9	+16.7
4	208.5	2.53	225.9	+17.4
5	228.2	1.81	237.0	+8.8
6	239.2	20.54	251.0	+11.8
7	242.9	1.17	336.3	+93.4
8	375.4	0.27	381.6	+6.2
9	398.5	1.76	413.6	+15.1
10	413.6	0.53	419.9	+6.3
11	417.6	1.11	426.8	+9.2
12	434.6	0.33	450.1	+15.5
13	537.2	37.42	547.9	+10.7
14	542.2	0.08	560.8	+18.6
15	553.4	2.71	570.3	+17.0
16	565.9	17.60	601.3	+35.4
17	588.1	1.46	620.6	+32.5
18	642.4	36.61	662.9	+20.5
19	656.8	10.84	687.4	+30.6
20	674.5	0.07	692.0	+17.5
21	707.6	4.16	713.4	+5.8
22	759.2	17.73	769.1	+9.9
23	792.1	5.77	806.7	+14.6
24	828.0	41.74	843.4	+15.4
25	833.5	10.46	847.0	+13.4
26	882.3	5.56	897.6	+15.3
27	882.8	7.04	901.5	+18.7
28	952.0	0.83	982.1	+30.2
29	963.1	0.30	996.3	+33.2
30	990.6	0.08	1018.5	+27.9
31	995.6	3.49	1020.9	+25.3
32	1026.6	16.35	1045.5	+18.9
33	1064.7	1.63	1077.5	+12.7
34	1172.4	1.19	1166.1	-6.3
35	1189.9	2.45	1181.0	-8.9
36	1194.9	0.13	1201.1	+6.3
37	1236.3	2.60	1238.2	+1.9
38	1250.7	0.76	1260.7	+10.1
39	1300.8	10.20	1308.7	+7.9
40	1356.4	33.71	1371.0	+14.7
41	1395.1	13.95	1393.3	-1.8
42	1406.8	0.59	1413.4	+6.5
43	1466.8	0.49	1481.9	+15.1
44	1504.6	1.55	1519.3	+14.7
45	1552.8	15.34	1579.1	+26.4
46	1599.6	9.75	1633.5	+33.9
47	1651.5	1.40	1682.3	+30.7
48	1675.5	2.15	1719.8	+44.3
49	2212.3	6.01	2251.2	+38.9
50	2681.5	9.90	2733.0	+51.5
51	3182.0	1.59	3225.2	+43.2
52	3191.1	1.19	3234.6	+43.5
53	3193.5	13.64	3236.7	+43.2
54	3205.0	28.63	3248.7	+43.7
55	3214.8	18.81	3258.9	+44.1
56	3217.4	10.89	3260.3	+42.9
57	3492.4	102.65	3527.0	+34.6

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 28 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, 2026-09-26 01:58:26 → 2026-09-26 02:48:16, 2990 s, peak 4.16 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