fluorene+SH C13H10S

A2_3b6ae59b2d · SMILES Sc1ccc2c(c1)Cc1ccccc1-2 · InChIKey FYOGYKWMXNQGFJ-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

47 infrared-active bands (500–3500 cm⁻¹); the strongest at 782 cm⁻¹ (12.8 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 — 2026-09-22, ubuntu-32gb-hel1-12
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.

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Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)

66 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	62.0	0.70	76.0	+14.0
2	82.4	20.96	149.8	+67.4
3	134.3	0.01	167.5	+33.2
4	157.6	0.59	191.2	+33.6
5	184.7	0.42	245.6	+60.9
6	243.9	5.55	263.6	+19.7
7	261.4	1.23	268.5	+7.1
8	329.1	0.44	341.8	+12.8
9	354.2	0.56	360.7	+6.4
10	427.2	3.82	437.4	+10.2
11	441.4	0.70	451.0	+9.6
12	504.6	0.83	510.6	+6.1
13	504.8	4.81	513.4	+8.7
14	508.9	1.53	519.5	+10.5
15	560.5	0.47	565.0	+4.5
16	583.5	1.01	598.0	+14.5
17	652.5	1.67	657.5	+5.0
18	680.5	0.29	687.2	+6.8
19	709.9	0.00	727.9	+18.0
20	748.2	23.25	762.4	+14.1
21	762.4	2.99	770.4	+8.0
22	782.2	38.69	797.3	+15.1
23	828.5	11.56	842.8	+14.3
24	833.9	0.37	848.7	+14.8
25	876.7	0.50	893.9	+17.1
26	883.7	4.69	897.0	+13.3
27	883.9	15.82	905.9	+22.0
28	932.8	0.00	962.4	+29.6
29	939.1	0.02	970.8	+31.7
30	945.0	8.44	973.1	+28.2
31	976.6	2.94	994.8	+18.2
32	980.6	1.19	1013.0	+32.4
33	1024.2	2.51	1032.5	+8.4
34	1057.6	2.65	1068.4	+10.8
35	1106.9	28.44	1119.2	+12.3
36	1128.9	3.09	1139.8	+10.9
37	1161.4	1.50	1167.8	+6.4
38	1168.9	0.00	1187.0	+18.0
39	1188.8	1.41	1190.0	+1.1
40	1202.0	1.33	1212.9	+11.0
41	1215.9	20.05	1225.5	+9.6
42	1235.2	0.45	1243.0	+7.8
43	1267.1	6.32	1268.3	+1.1
44	1325.3	4.77	1311.5	-13.8
45	1339.5	0.09	1325.0	-14.5
46	1349.3	13.15	1355.8	+6.6
47	1385.7	1.41	1375.7	-10.1
48	1464.3	18.79	1479.9	+15.6
49	1479.7	7.50	1494.8	+15.1
50	1500.2	30.60	1513.0	+12.8
51	1514.9	13.81	1532.5	+17.6
52	1527.2	9.05	1550.3	+23.0
53	1620.8	6.52	1653.7	+32.9
54	1638.9	0.73	1672.2	+33.3
55	1660.9	31.82	1703.2	+42.3
56	1666.2	0.50	1710.0	+43.8
57	2695.4	12.12	2740.2	+44.8
58	3037.2	14.36	3080.8	+43.7
59	3065.0	11.42	3119.8	+54.8
60	3177.4	6.66	3220.8	+43.4
61	3182.5	9.67	3226.3	+43.8
62	3183.6	8.58	3227.0	+43.4
63	3184.1	2.38	3227.4	+43.3
64	3194.4	23.83	3237.8	+43.4
65	3199.7	23.46	3243.7	+44.0
66	3206.3	37.70	3249.1	+42.8

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 3 cm⁻¹; wb97x max |Δω| 20 cm⁻¹.

Provenance

Releases: layerA2_2026-09-23, layerA2_2026-09-23b, layerA2_2026-09-24
Entered the corpus as: substituted three- and four-ring cores, enumerated from the parents (layer A′) (layer A2)
Run: ubuntu-32gb-hel1-12, 2026-09-22 10:43:47 → 2026-09-22 11:55:27, 4299 s, peak 5.11 GB, deck 97ed2d67c66b
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