biphenyl+NO2 C12H9NO2

B_477b567fed · SMILES O=[N+]([O-])c1ccccc1-c1ccccc1 · InChIKey YOJKKXRJMXIKSR-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

40 infrared-active bands (500–3500 cm⁻¹); the strongest at 1404 cm⁻¹ (7.1 µm), 206 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 — 2026-09-29, ubuntu-32gb-hel1-14
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)

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	38.3	0.30	81.3	+43.0
2	59.6	0.48	92.7	+33.1
3	83.5	1.58	108.6	+25.2
4	108.3	0.27	141.1	+32.8
5	153.2	0.53	172.0	+18.8
6	212.2	2.55	224.7	+12.6
7	275.7	0.11	282.9	+7.2
8	305.1	1.09	314.8	+9.6
9	334.5	1.20	348.0	+13.5
10	407.9	1.21	416.1	+8.3
11	415.9	0.11	428.9	+12.9
12	421.6	1.04	434.3	+12.7
13	526.6	4.65	538.5	+11.8
14	552.8	2.12	562.8	+10.0
15	587.2	2.00	597.9	+10.7
16	627.5	4.39	631.6	+4.2
17	634.6	0.28	638.9	+4.3
18	680.1	8.13	688.6	+8.5
19	711.9	26.75	725.5	+13.5
20	721.2	1.82	740.3	+19.0
21	757.7	52.85	771.0	+13.3
22	767.0	3.96	777.6	+10.5
23	785.5	18.16	803.8	+18.2
24	803.8	9.61	825.3	+21.5
25	860.4	1.78	879.3	+18.9
26	864.0	27.70	881.6	+17.7
27	897.9	0.80	916.6	+18.7
28	933.5	1.82	956.2	+22.8
29	968.2	1.19	993.2	+25.1
30	969.6	0.47	1003.0	+33.4
31	997.2	0.49	1024.2	+27.0
32	997.5	0.27	1025.3	+27.8
33	1017.9	2.00	1028.5	+10.6
34	1027.9	4.32	1037.9	+10.0
35	1065.3	0.19	1077.8	+12.5
36	1074.5	0.43	1086.3	+11.8
37	1112.5	4.27	1123.2	+10.7
38	1119.3	7.67	1133.1	+13.8
39	1173.4	3.08	1186.9	+13.5
40	1194.4	0.03	1190.5	-4.0
41	1196.9	0.72	1191.2	-5.7
42	1217.5	0.65	1224.0	+6.5
43	1282.7	1.21	1283.0	+0.3
44	1308.5	7.70	1307.7	-0.8
45	1340.4	0.15	1312.0	-28.4
46	1354.6	10.89	1344.3	-10.3
47	1369.4	1.64	1368.9	-0.6
48	1404.3	206.05	1449.8	+45.5
49	1476.5	4.48	1489.4	+12.9
50	1498.8	4.67	1512.5	+13.8
51	1521.2	20.47	1535.8	+14.6
52	1550.0	0.97	1571.3	+21.3
53	1617.9	45.37	1649.0	+31.1
54	1634.6	112.41	1664.7	+30.1
55	1641.1	24.20	1675.2	+34.1
56	1662.9	0.58	1699.3	+36.4
57	1666.9	80.09	1708.2	+41.3
58	3183.2	2.96	3226.0	+42.8
59	3188.3	0.04	3231.5	+43.1
60	3195.4	6.79	3237.9	+42.5
61	3196.7	11.28	3239.7	+43.0
62	3204.0	30.44	3246.9	+43.0
63	3209.7	5.96	3252.1	+42.5
64	3213.2	24.37	3255.5	+42.4
65	3217.8	12.69	3260.1	+42.3
66	3242.6	1.49	3285.1	+42.5

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: none yet
Entered the corpus as: cores with one or two substituents, enumerated from the parents (layer B)
Run: ubuntu-32gb-hel1-14, 2026-09-29 19:56:46 → 2026-09-29 21:22:26, 5140 s, peak 5.45 GB, deck 9e27bf8e9348
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