pyrrole+OH C4H5NO

B_0b1e9970cd · SMILES Oc1cc[nH]c1 · InChIKey ZPOROQKDAPEMOL-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)

27 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	246.0	322.7	+76.7
2	292.9	348.5	+55.6
3	356.7	412.2	+55.5
4	400.4	428.9	+28.5
5	593.7	634.4	+40.7
6	624.2	645.2	+21.0
7	665.7	670.1	+4.4
8	665.8	694.1	+28.3
9	730.8	761.5	+30.8
10	816.6	853.9	+37.3
11	897.3	902.4	+5.1
12	990.4	1000.5	+10.1
13	1085.0	1087.4	+2.4
14	1086.9	1095.3	+8.4
15	1172.5	1181.6	+9.0
16	1185.5	1208.8	+23.2
17	1316.7	1331.4	+14.8
18	1343.3	1353.7	+10.4
19	1473.0	1492.9	+19.9
20	1496.0	1519.0	+23.0
21	1558.8	1578.4	+19.7
22	1639.0	1665.8	+26.8
23	3268.2	3308.4	+40.2
24	3274.7	3315.6	+40.9
25	3286.2	3326.8	+40.7
26	3679.4	3726.9	+47.5
27	3760.6	3800.5	+40.0

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-27, 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| 17 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, 2026-09-27 21:28:06 → 2026-09-27 21:34:04, 358 s, peak 1.52 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Source files: corpus factory · manifest