pyridine+COOH+vinyl C8H7NO2

B_0f65cb0031 · SMILES C=Cc1ccc(C(=O)O)cn1 · InChIKey HCAXAGYQQYQNTF-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	45.6	80.8	+35.2
2	70.0	103.2	+33.2
3	113.6	131.4	+17.8
4	159.4	171.8	+12.3
5	259.4	270.2	+10.7
6	261.3	276.2	+14.9
7	342.7	347.6	+4.9
8	412.2	427.5	+15.3
9	447.1	462.5	+15.4
10	484.9	489.0	+4.1
11	520.9	526.9	+6.0
12	604.1	613.6	+9.5
13	608.5	642.4	+33.9
14	655.0	659.7	+4.7
15	655.3	673.9	+18.6
16	720.8	733.0	+12.3
17	752.5	773.0	+20.6
18	819.6	837.6	+18.0
19	841.5	852.1	+10.7
20	866.9	885.3	+18.4
21	945.6	981.0	+35.4
22	986.6	1010.4	+23.8
23	995.4	1016.4	+21.0
24	1036.2	1045.6	+9.3
25	1049.0	1056.5	+7.5
26	1052.6	1066.8	+14.2
27	1124.7	1140.7	+16.0
28	1174.4	1179.3	+4.9
29	1221.7	1246.8	+25.1
30	1254.4	1254.9	+0.5
31	1316.6	1309.4	-7.2
32	1330.7	1325.1	-5.5
33	1344.9	1346.5	+1.7
34	1391.1	1413.0	+21.8
35	1432.9	1452.8	+19.9
36	1475.5	1482.6	+7.1
37	1527.0	1549.8	+22.8
38	1608.4	1640.9	+32.5
39	1652.2	1696.5	+44.3
40	1712.0	1744.5	+32.5
41	1823.2	1857.9	+34.7
42	3172.0	3210.2	+38.2
43	3191.8	3236.6	+44.7
44	3203.0	3246.3	+43.3
45	3212.6	3257.1	+44.5
46	3232.3	3275.3	+43.0
47	3252.1	3295.8	+43.7
48	3696.9	3736.8	+39.9

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-28, 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| 2 cm⁻¹; wb97x max |Δω| 16 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-hel1-21, 2026-09-28 01:19:04 → 2026-09-28 01:52:25, 2001 s, peak 3.21 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Source files: corpus factory · manifest