carbazole C12H9N

A_8152ea74fd · SMILES c1ccc2c(c1)[nH]c1ccccc12 · InChIKey UJOBWOGCFQCDNV-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

32 infrared-active bands (500–3500 cm⁻¹); the strongest at 1270 cm⁻¹ (7.9 µm), 78 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 — 2026-09-18, ubuntu-32gb-hel1-2
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)

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	104.0	5.11	120.6	+16.5
2	152.2	0.00	164.5	+12.3
3	219.3	0.28	227.1	+7.8
4	280.7	29.30	297.5	+16.8
5	297.3	0.00	308.9	+11.6
6	348.6	67.71	365.6	+17.1
7	433.4	6.51	439.5	+6.1
8	435.0	1.14	447.4	+12.4
9	455.2	0.00	466.4	+11.3
10	514.1	3.99	519.4	+5.2
11	563.4	0.16	567.6	+4.1
12	576.6	10.71	592.8	+16.2
13	585.2	0.00	599.4	+14.3
14	631.3	6.10	635.2	+3.9
15	669.4	0.57	675.0	+5.6
16	741.2	44.72	756.0	+14.8
17	754.5	0.00	768.6	+14.1
18	760.2	1.42	769.4	+9.2
19	763.2	61.39	783.3	+20.1
20	790.7	0.00	809.6	+19.0
21	856.3	0.34	873.5	+17.3
22	861.9	0.00	882.3	+20.4
23	865.6	2.26	887.4	+21.7
24	889.5	0.27	897.3	+7.8
25	924.3	1.46	963.6	+39.3
26	924.5	0.00	964.7	+40.2
27	964.6	0.00	999.0	+34.4
28	966.6	0.00	1000.1	+33.6
29	1020.5	4.52	1028.2	+7.8
30	1046.0	0.27	1059.0	+13.0
31	1051.1	3.59	1062.6	+11.5
32	1136.5	2.18	1145.7	+9.1
33	1149.8	8.23	1158.5	+8.6
34	1184.0	6.63	1179.4	-4.6
35	1191.5	0.23	1190.4	-1.1
36	1241.3	6.17	1247.9	+6.6
37	1246.2	0.67	1256.2	+10.0
38	1270.1	77.78	1278.3	+8.3
39	1322.4	4.75	1328.8	+6.5
40	1349.4	0.34	1350.4	+1.0
41	1370.7	66.16	1355.9	-14.8
42	1387.1	9.56	1369.1	-17.9
43	1442.7	11.62	1448.6	+5.9
44	1493.8	32.56	1510.0	+16.2
45	1511.2	32.79	1523.7	+12.4
46	1533.6	0.01	1554.5	+20.9
47	1544.7	34.18	1564.1	+19.4
48	1631.3	0.00	1663.0	+31.7
49	1636.3	1.88	1668.6	+32.4
50	1666.8	39.69	1702.0	+35.2
51	1681.6	3.55	1726.6	+45.0
52	3181.0	0.09	3224.3	+43.3
53	3181.7	3.17	3224.8	+43.1
54	3186.8	4.14	3230.7	+43.8
55	3188.2	0.94	3231.4	+43.2
56	3197.5	4.89	3241.0	+43.5
57	3198.0	61.43	3241.3	+43.3
58	3209.0	28.23	3251.8	+42.9
59	3209.3	34.74	3252.4	+43.1
60	3664.2	47.91	3711.6	+47.4

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 5 cm⁻¹.

Provenance

Releases: layerA2_2026-09-23, layerA2_2026-09-23b, layerA2_2026-09-24, layerA_2026-09-22
Entered the corpus as: parent molecules chosen by hand (benzene, naphthalene, the PAH cores and their relatives) (layer A)
Run: ubuntu-32gb-hel1-2, 2026-09-18 20:32:54 → 2026-09-18 21:20:02, 2827 s, peak 4.26 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