acenaphthylene+CHO C13H8O

A2_0b93df3e1a · SMILES O=Cc1cc2c3c(cccc3c1)C=C2 · InChIKey AKZTWYIBFDPJLE-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

35 infrared-active bands (500–3500 cm⁻¹); the strongest at 1795 cm⁻¹ (5.6 µm), 323 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 — 2026-09-20, ubuntu-32gb-hel1-9
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)

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	79.2	1.45	100.9	+21.6
2	170.4	10.56	187.9	+17.5
3	177.3	6.74	198.9	+21.6
4	197.3	2.09	204.3	+7.0
5	233.3	1.81	240.5	+7.2
6	308.3	0.20	320.2	+11.8
7	353.6	0.40	357.3	+3.7
8	381.7	0.04	394.8	+13.2
9	451.1	10.99	456.0	+4.9
10	471.2	0.71	476.2	+5.0
11	496.7	0.40	505.3	+8.6
12	557.3	5.35	561.9	+4.6
13	589.2	11.05	593.7	+4.5
14	606.2	0.58	615.9	+9.7
15	619.7	0.01	625.5	+5.8
16	679.5	0.18	687.7	+8.2
17	689.6	17.62	695.7	+6.1
18	704.2	2.23	708.9	+4.7
19	751.0	35.08	763.5	+12.5
20	784.5	15.37	797.1	+12.5
21	804.9	20.35	808.6	+3.7
22	844.9	4.26	854.4	+9.5
23	861.9	0.65	868.3	+6.4
24	895.6	34.86	914.7	+19.0
25	923.1	0.37	951.0	+27.8
26	936.1	2.13	963.2	+27.1
27	950.7	7.50	972.5	+21.8
28	964.0	10.16	976.9	+12.9
29	976.8	1.42	1007.8	+31.0
30	1029.1	0.43	1052.3	+23.2
31	1047.8	1.55	1059.0	+11.3
32	1057.4	0.63	1067.8	+10.4
33	1100.9	8.02	1111.8	+10.9
34	1120.4	14.41	1126.5	+6.0
35	1167.4	97.68	1171.5	+4.2
36	1201.8	2.53	1199.7	-2.2
37	1234.2	1.31	1238.3	+4.1
38	1259.8	1.81	1256.0	-3.8
39	1299.4	13.75	1307.0	+7.6
40	1351.1	2.89	1349.1	-2.0
41	1382.5	8.86	1399.4	+16.8
42	1404.7	9.14	1415.6	+11.0
43	1448.5	10.88	1453.0	+4.5
44	1459.6	45.72	1469.9	+10.4
45	1487.3	11.03	1494.6	+7.3
46	1505.6	17.83	1526.7	+21.1
47	1517.4	3.51	1550.8	+33.3
48	1563.6	7.38	1588.9	+25.3
49	1651.7	7.23	1686.0	+34.3
50	1660.7	0.48	1694.6	+33.8
51	1675.3	44.90	1719.1	+43.8
52	1794.5	322.55	1829.5	+35.0
53	2908.9	143.66	2959.8	+50.9
54	3176.4	8.39	3220.1	+43.7
55	3184.6	0.24	3227.1	+42.5
56	3193.1	16.04	3235.9	+42.8
57	3208.3	31.68	3251.1	+42.7
58	3215.0	1.46	3257.7	+42.7
59	3229.8	1.51	3271.2	+41.4
60	3248.7	16.08	3290.9	+42.2

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 5 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-hel1-9, 2026-09-20 13:38:08 → 2026-09-20 14:40:55, 3766 s, peak 4.66 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