biphenylene+NO2 C12H7NO2

A2_3a06a80d61 · SMILES O=[N+]([O-])c1cccc2c1-c1ccccc1-2 · InChIKey XRMZDXXKPLLCFE-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

36 infrared-active bands (500–3500 cm⁻¹); the strongest at 1398 cm⁻¹ (7.2 µm), 306 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-hel1-11
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	60.9	0.00	109.7	+48.8
2	102.2	0.40	125.7	+23.5
3	110.9	2.39	135.6	+24.7
4	125.3	1.52	136.4	+11.1
5	197.2	0.63	210.6	+13.4
6	272.9	0.57	287.0	+14.1
7	325.9	0.08	333.4	+7.5
8	361.0	0.85	365.8	+4.9
9	389.1	1.07	399.7	+10.6
10	400.9	2.30	406.1	+5.2
11	468.3	0.01	481.5	+13.3
12	490.6	0.00	494.8	+4.2
13	516.2	1.62	522.5	+6.3
14	583.8	0.00	599.1	+15.3
15	609.7	0.16	615.8	+6.2
16	631.3	0.78	634.6	+3.3
17	666.2	7.78	673.0	+6.8
18	707.3	0.15	725.7	+18.3
19	739.1	2.51	748.8	+9.7
20	747.0	62.08	765.6	+18.6
21	765.5	33.15	778.6	+13.1
22	796.4	7.80	811.2	+14.8
23	799.3	19.22	813.6	+14.3
24	832.9	3.07	845.1	+12.2
25	902.2	0.39	917.6	+15.4
26	903.3	19.68	919.3	+16.0
27	922.5	1.18	947.4	+24.8
28	941.6	2.85	965.7	+24.1
29	975.2	0.68	1004.7	+29.5
30	984.6	0.06	1010.7	+26.1
31	1001.5	10.28	1016.4	+14.9
32	1019.2	5.06	1024.7	+5.4
33	1043.1	10.29	1049.7	+6.5
34	1087.7	7.59	1096.1	+8.5
35	1112.8	1.10	1123.3	+10.4
36	1150.4	35.46	1156.2	+5.8
37	1160.7	3.14	1169.7	+9.0
38	1191.4	7.28	1188.3	-3.1
39	1198.8	1.81	1201.5	+2.7
40	1244.4	18.85	1257.5	+13.1
41	1314.3	0.82	1286.6	-27.7
42	1326.3	91.24	1320.1	-6.2
43	1398.2	306.48	1433.4	+35.2
44	1424.2	3.38	1446.5	+22.3
45	1467.9	17.47	1480.4	+12.5
46	1485.5	13.30	1505.1	+19.5
47	1498.2	4.16	1513.9	+15.6
48	1527.6	0.73	1544.9	+17.3
49	1619.4	112.16	1648.0	+28.6
50	1643.6	34.06	1679.0	+35.4
51	1649.9	28.30	1695.1	+45.2
52	1668.5	40.10	1710.0	+41.5
53	1727.0	16.91	1754.0	+27.0
54	3189.8	1.28	3232.3	+42.5
55	3202.0	7.77	3244.5	+42.5
56	3204.1	13.98	3246.4	+42.3
57	3214.0	25.13	3256.3	+42.3
58	3217.3	14.23	3259.6	+42.3
59	3234.9	3.70	3275.7	+40.8
60	3248.9	1.66	3291.5	+42.6

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 6 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-hel1-11, 2026-09-22 15:40:16 → 2026-09-22 16:49:56, 4179 s, peak 5.14 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