biphenylene+CHO C13H8O

A2_32e53836ea · SMILES O=Cc1cccc2c1-c1ccccc1-2 · InChIKey YPDSRVKCAIZYIA-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

38 infrared-active bands (500–3500 cm⁻¹); the strongest at 1793 cm⁻¹ (5.6 µm), 325 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

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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	84.1	0.87	107.6	+23.5
2	109.8	1.27	123.0	+13.2
3	125.9	1.84	131.5	+5.6
4	163.3	5.58	178.5	+15.2
5	230.0	5.43	230.8	+0.8
6	258.7	6.79	268.2	+9.5
7	331.9	0.51	335.9	+4.0
8	391.1	1.55	395.5	+4.4
9	400.2	1.28	404.8	+4.5
10	404.7	0.26	412.1	+7.4
11	468.3	0.03	480.6	+12.3
12	495.2	1.40	500.2	+5.0
13	586.3	5.55	589.6	+3.4
14	592.0	1.03	605.7	+13.7
15	619.7	2.18	624.9	+5.2
16	666.2	5.47	670.3	+4.1
17	717.5	1.88	737.4	+19.8
18	734.8	3.36	743.4	+8.6
19	759.3	60.75	771.2	+11.9
20	774.3	21.69	782.8	+8.5
21	787.6	24.40	801.0	+13.4
22	828.4	3.11	841.4	+13.0
23	889.1	13.03	899.1	+10.0
24	895.5	0.01	918.4	+22.9
25	922.9	1.80	955.4	+32.5
26	928.1	1.47	960.8	+32.7
27	976.7	0.20	1002.6	+25.9
28	977.2	0.43	1008.2	+31.0
29	999.1	14.76	1008.8	+9.7
30	1022.4	2.54	1027.6	+5.2
31	1022.8	0.13	1036.0	+13.2
32	1045.5	12.30	1053.1	+7.6
33	1086.7	2.87	1095.5	+8.9
34	1119.5	1.30	1128.3	+8.8
35	1147.9	16.86	1157.4	+9.4
36	1177.5	15.89	1172.4	-5.1
37	1196.5	4.88	1187.5	-9.1
38	1213.4	0.56	1223.1	+9.7
39	1270.8	87.53	1269.4	-1.4
40	1315.3	2.43	1300.9	-14.4
41	1324.8	52.34	1322.3	-2.5
42	1414.5	21.02	1426.2	+11.7
43	1443.0	1.74	1447.3	+4.2
44	1469.8	19.34	1481.7	+11.9
45	1493.7	4.05	1509.3	+15.6
46	1497.2	7.86	1514.0	+16.8
47	1526.8	2.84	1542.2	+15.4
48	1632.6	9.90	1681.4	+48.8
49	1650.5	12.33	1686.7	+36.2
50	1653.7	2.27	1693.6	+39.9
51	1720.6	12.03	1748.3	+27.7
52	1792.5	325.22	1827.2	+34.7
53	2917.7	88.14	2967.7	+50.0
54	3187.7	0.26	3230.3	+42.6
55	3193.7	7.56	3236.4	+42.7
56	3199.7	8.08	3242.1	+42.4
57	3209.1	15.09	3251.4	+42.3
58	3210.0	21.87	3252.7	+42.6
59	3215.0	23.60	3257.3	+42.3
60	3221.8	8.11	3264.7	+42.8

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 11 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, 2026-09-21 23:14:48 → 2026-09-22 00:07:58, 3189 s, peak 4.44 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