isoquinoline+CONH2 C10H8N2O

B_1863d5f90f · SMILES NC(=O)c1ccc2cnccc2c1 · InChIKey MBJVWMQHKCGMLZ-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 1788 cm⁻¹ (5.6 µm), 273 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 — 2026-09-27, ubuntu-32gb-hel1-16
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

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.

Notify me when this molecule climbs the ladder: open a GitHub issue — you are subscribed to it and we close it with a link when the page changes. No e-mail address is stored by this site.

Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)

57 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	59.4	7.58	93.3	+33.9
2	87.2	1.69	101.8	+14.6
3	164.9	6.25	174.9	+10.1
4	189.4	1.24	195.9	+6.5
5	236.8	3.43	250.7	+13.9
6	324.0	0.30	328.4	+4.4
7	357.5	4.88	365.2	+7.7
8	391.3	1.08	404.0	+12.7
9	416.3	165.15	453.0	+36.8
10	458.4	21.96	473.9	+15.5
11	488.7	2.60	496.7	+8.0
12	522.6	13.20	534.5	+11.9
13	539.3	0.28	543.6	+4.2
14	571.3	42.81	590.4	+19.1
15	587.5	29.26	596.6	+9.0
16	651.6	0.08	658.9	+7.3
17	662.2	4.06	675.3	+13.1
18	702.4	15.65	710.8	+8.4
19	764.2	37.35	775.1	+10.9
20	795.6	0.13	806.0	+10.5
21	802.0	1.02	810.8	+8.8
22	833.4	10.64	843.7	+10.3
23	863.4	18.34	871.2	+7.8
24	892.2	13.00	902.3	+10.1
25	922.4	14.68	937.6	+15.2
26	954.2	2.36	971.9	+17.7
27	969.8	11.29	979.0	+9.2
28	983.2	0.64	1009.5	+26.3
29	996.0	0.31	1017.7	+21.8
30	1071.7	1.48	1082.7	+11.0
31	1100.1	7.13	1115.4	+15.3
32	1133.4	3.47	1145.6	+12.2
33	1172.6	2.48	1156.5	-16.1
34	1206.6	4.93	1193.6	-13.1
35	1246.1	20.68	1247.2	+1.1
36	1288.1	1.59	1291.6	+3.5
37	1300.4	14.37	1308.3	+7.9
38	1374.4	191.14	1375.3	+0.8
39	1386.7	15.15	1398.0	+11.3
40	1398.8	45.63	1412.1	+13.2
41	1429.9	8.76	1433.8	+4.0
42	1449.9	7.12	1464.2	+14.2
43	1514.8	4.18	1532.1	+17.3
44	1542.7	4.54	1571.5	+28.8
45	1620.8	9.55	1653.4	+32.6
46	1639.9	29.12	1665.6	+25.7
47	1645.7	150.06	1671.2	+25.5
48	1682.5	7.96	1731.1	+48.6
49	1788.2	273.42	1821.0	+32.9
50	3150.7	25.71	3195.3	+44.6
51	3182.4	8.08	3225.8	+43.4
52	3190.1	15.81	3233.5	+43.4
53	3191.6	3.29	3236.2	+44.6
54	3201.2	32.81	3244.5	+43.3
55	3232.4	2.70	3275.3	+42.9
56	3578.8	39.86	3627.0	+48.2
57	3697.6	27.68	3746.4	+48.9

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 13 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-hel1-16, 2026-09-27 07:10:50 → 2026-09-27 07:56:21, 2730 s, peak 4.04 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