fluorene C13H10

A_e72997e726 · SMILES c1ccc2c(c1)Cc1ccccc1-2 · InChIKey NIHNNTQXNPWCJQ-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

30 infrared-active bands (500–3500 cm⁻¹); the strongest at 759 cm⁻¹ (13.2 µm), 90 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 — 2026-09-19, ubuntu-32gb-hel1-2
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

Through the pipeline

This molecule has a recorded run: see it go through the pipeline, station by station, with its spectrum and certificate.

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)

63 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	99.7	0.33	114.7	+15.0
2	138.8	0.00	151.7	+12.9
3	215.7	0.19	221.3	+5.6
4	245.6	5.32	266.0	+20.4
5	279.8	0.00	289.9	+10.1
6	419.6	0.34	423.2	+3.6
7	425.9	3.57	437.6	+11.7
8	442.9	0.00	451.6	+8.7
9	483.5	0.91	497.1	+13.6
10	496.8	0.23	500.4	+3.7
11	552.4	0.20	556.8	+4.3
12	577.1	0.00	588.3	+11.2
13	636.2	7.93	639.9	+3.7
14	643.9	0.27	647.6	+3.7
15	711.9	1.72	728.6	+16.6
16	745.5	0.00	759.3	+13.8
17	757.6	0.04	762.7	+5.1
18	759.0	89.59	769.4	+10.4
19	801.6	0.00	815.4	+13.8
20	816.6	0.23	826.0	+9.4
21	853.6	0.11	860.1	+6.6
22	875.1	0.68	895.2	+20.1
23	883.5	0.00	905.6	+22.1
24	927.8	0.14	954.1	+26.4
25	938.3	0.00	970.9	+32.6
26	977.4	2.19	997.2	+19.8
27	978.5	0.00	1009.9	+31.5
28	982.3	1.32	1012.0	+29.7
29	1024.7	1.45	1033.1	+8.4
30	1054.8	0.51	1064.1	+9.3
31	1059.1	3.92	1067.2	+8.1
32	1122.8	1.41	1129.6	+6.8
33	1138.3	0.20	1146.4	+8.1
34	1167.4	0.00	1181.3	+13.8
35	1186.7	0.08	1184.1	-2.6
36	1190.3	0.00	1190.6	+0.3
37	1202.0	3.32	1210.6	+8.6
38	1214.8	2.17	1225.7	+10.9
39	1232.4	1.67	1241.9	+9.4
40	1264.8	3.26	1267.1	+2.3
41	1331.8	0.11	1323.6	-8.3
42	1341.5	0.53	1334.3	-7.1
43	1362.8	10.92	1363.8	+1.0
44	1392.6	0.23	1375.2	-17.4
45	1480.5	7.67	1495.8	+15.3
46	1494.9	7.99	1507.8	+13.0
47	1501.0	20.08	1511.6	+10.6
48	1526.1	0.02	1543.2	+17.0
49	1527.5	6.90	1549.6	+22.1
50	1636.5	1.18	1667.4	+30.9
51	1640.9	0.27	1674.6	+33.7
52	1665.2	0.24	1703.7	+38.5
53	1666.0	3.31	1711.7	+45.7
54	3034.8	16.52	3078.4	+43.6
55	3061.7	13.01	3116.7	+54.9
56	3176.3	3.26	3219.6	+43.3
57	3176.8	8.51	3219.9	+43.1
58	3182.1	2.78	3226.0	+43.8
59	3183.8	6.05	3227.0	+43.2
60	3193.5	7.97	3237.1	+43.6
61	3194.8	51.07	3237.5	+42.7
62	3206.2	63.90	3249.1	+43.0
63	3207.1	6.31	3249.8	+42.7

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 9 cm⁻¹.

Provenance

Releases: layerA2_2026-09-23, layerA2_2026-09-23b, layerA2_2026-09-24, layerA_2026-09-22
Entered the corpus as: parent molecules chosen by hand (benzene, naphthalene, the PAH cores and their relatives) (layer A)
Run: ubuntu-32gb-hel1-2, 2026-09-19 08:18:09 → 2026-09-19 09:12:57, 3287 s, peak 4.49 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