dibenzofuran+CH3 C13H10O

A2_34bb1210bc · SMILES Cc1ccc2oc3ccccc3c2c1 · InChIKey VTKMFJSESAHMLR-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

50 infrared-active bands (500–3500 cm⁻¹); the strongest at 1234 cm⁻¹ (8.1 µm), 131 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

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)

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	35.3	0.16	102.5	+67.3
2	93.5	0.92	116.8	+23.3
3	130.9	0.19	140.6	+9.7
4	180.8	0.82	187.1	+6.3
5	221.0	0.08	229.8	+8.8
6	301.6	0.00	312.6	+10.9
7	339.6	0.99	345.3	+5.7
8	371.9	2.42	384.5	+12.6
9	402.3	2.16	406.1	+3.7
10	435.4	2.40	443.1	+7.7
11	454.7	0.00	458.8	+4.1
12	520.1	1.17	524.2	+4.1
13	539.8	0.87	544.0	+4.3
14	574.5	1.40	587.7	+13.2
15	597.7	3.67	609.9	+12.2
16	635.2	6.06	639.5	+4.3
17	648.9	1.18	653.4	+4.5
18	734.8	3.75	748.3	+13.4
19	742.1	1.88	754.1	+12.0
20	760.0	28.10	777.3	+17.3
21	772.0	21.16	788.4	+16.5
22	818.3	5.87	826.5	+8.3
23	822.5	31.49	834.7	+12.2
24	865.0	19.72	872.4	+7.3
25	867.7	0.51	884.7	+17.0
26	890.0	3.35	908.4	+18.4
27	904.8	2.07	915.2	+10.4
28	932.6	1.60	961.9	+29.2
29	945.3	0.27	970.3	+25.0
30	972.0	0.03	1004.1	+32.1
31	1016.3	2.50	1022.7	+6.4
32	1039.5	0.34	1047.8	+8.3
33	1055.1	18.11	1060.8	+5.7
34	1075.4	4.01	1085.0	+9.5
35	1131.8	6.84	1139.3	+7.5
36	1154.8	8.84	1156.4	+1.6
37	1181.4	2.95	1182.3	+0.9
38	1198.5	3.50	1207.5	+9.0
39	1234.4	130.74	1244.8	+10.3
40	1246.3	20.63	1259.4	+13.0
41	1284.9	11.48	1294.7	+9.8
42	1315.8	13.65	1320.0	+4.3
43	1337.6	3.09	1330.8	-6.8
44	1371.2	9.50	1347.1	-24.1
45	1393.8	4.60	1371.3	-22.5
46	1444.4	0.61	1455.7	+11.3
47	1473.9	1.58	1488.0	+14.1
48	1495.5	33.42	1512.0	+16.6
49	1515.2	5.29	1522.4	+7.2
50	1519.6	29.81	1531.4	+11.8
51	1528.4	43.59	1547.2	+18.7
52	1538.5	10.37	1557.4	+18.9
53	1639.0	0.99	1673.3	+34.3
54	1645.0	2.18	1677.0	+32.0
55	1659.5	2.24	1695.3	+35.7
56	1685.5	0.69	1731.0	+45.5
57	3041.9	42.01	3076.9	+35.1
58	3092.6	21.99	3143.1	+50.5
59	3124.3	15.81	3171.6	+47.2
60	3183.5	13.87	3227.2	+43.7
61	3186.2	9.39	3230.1	+43.9
62	3188.5	3.57	3231.4	+42.8
63	3197.3	11.23	3240.4	+43.1
64	3210.2	27.57	3252.9	+42.7
65	3221.9	8.86	3264.3	+42.4
66	3225.3	9.56	3267.6	+42.3

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 3 cm⁻¹; wb97x max |Δω| 27 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 00:07:58 → 2026-09-22 01:11:25, 3806 s, peak 4.8 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