pyridine+COOH+vinyl C8H7NO2

B_05988f899b · SMILES C=Cc1cncc(C(=O)O)c1 · InChIKey TUEKKQIGYOTJRW-UHFFFAOYSA-N

Cheap level done

finite-difference Hessian noisy

finite-difference Hessian noisy (analytic check differs > 15 cm⁻¹). The finite-difference Hessian and the analytic Hessian of the same geometry differ by more than 15 cm⁻¹ on at least one frequency; the numerical route is the noisy one.

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

48 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP.

Band heights are not computed for this molecule yet (no dipole derivatives); positions only, at unit height. High wavenumbers on the left; the table below is the same data.

#	B3LYP (cm⁻¹)	ωB97X (cm⁻¹)	shift
1	23.2	6.8	-16.5
2	63.5	94.4	+30.9
3	149.7	158.0	+8.3
4	154.0	163.0	+9.1
5	211.9	212.0	+0.1
6	260.9	270.9	+10.0
7	360.3	365.0	+4.6
8	419.8	430.5	+10.8
9	427.4	436.3	+8.9
10	439.3	447.7	+8.4
11	537.1	542.6	+5.5
12	575.4	577.9	+2.4
13	614.3	648.2	+33.8
14	644.4	653.9	+9.5
15	679.1	696.2	+17.1
16	724.2	734.5	+10.3
17	739.2	742.5	+3.3
18	780.8	798.6	+17.8
19	924.1	934.8	+10.7
20	935.3	952.0	+16.7
21	938.0	963.5	+25.5
22	964.4	981.3	+16.9
23	987.4	1011.3	+23.8
24	1035.8	1042.2	+6.4
25	1040.2	1047.2	+7.0
26	1058.4	1059.6	+1.2
27	1124.3	1138.8	+14.6
28	1200.1	1212.4	+12.3
29	1215.1	1225.6	+10.5
30	1264.7	1266.4	+1.7
31	1311.2	1291.0	-20.1
32	1352.7	1351.1	-1.5
33	1370.2	1368.3	-1.9
34	1396.3	1419.1	+22.8
35	1456.2	1467.2	+11.0
36	1488.3	1506.4	+18.1
37	1496.7	1507.6	+10.8
38	1623.1	1661.8	+38.8
39	1648.6	1687.6	+39.0
40	1715.2	1749.3	+34.1
41	1827.3	1861.9	+34.6
42	3154.0	3197.6	+43.6
43	3174.5	3215.2	+40.7
44	3183.9	3227.2	+43.3
45	3211.3	3254.3	+43.0
46	3217.0	3260.5	+43.5
47	3254.3	3298.0	+43.7
48	3696.0	3735.8	+39.8

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-25, ubuntu-32gb-hel1-21
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

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Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 52 cm⁻¹.

Provenance

Releases: layerB_interim_2026-09-25
Entered the corpus as: cores with one or two substituents, enumerated from the parents (layer B)
Run: ubuntu-32gb-hel1-21, 2026-09-25 12:30:42 → 2026-09-25 13:03:26, 1963 s, peak 3.25 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Source files: corpus factory · manifest