pyridine+CH3+ethynyl C8H7N

B_17f1611949 · SMILES C#Cc1cnccc1C · InChIKey BHTSIYCRJMKMGP-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)

42 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	97.3	148.4	+51.1
2	137.0	161.9	+24.9
3	143.1	180.3	+37.3
4	215.3	234.3	+18.9
5	334.9	349.6	+14.7
6	365.6	381.4	+15.8
7	460.2	468.1	+7.9
8	482.0	492.4	+10.4
9	562.6	569.2	+6.7
10	564.2	596.0	+31.7
11	591.7	612.3	+20.6
12	605.5	637.7	+32.2
13	639.0	681.8	+42.8
14	749.3	763.1	+13.8
15	762.1	768.5	+6.4
16	843.4	854.1	+10.7
17	850.0	856.4	+6.4
18	950.7	967.0	+16.4
19	983.9	1010.6	+26.7
20	1020.1	1030.5	+10.4
21	1075.5	1087.1	+11.6
22	1098.3	1107.2	+8.9
23	1187.9	1200.0	+12.0
24	1229.8	1233.3	+3.4
25	1265.0	1265.7	+0.7
26	1301.2	1283.9	-17.3
27	1334.9	1341.0	+6.1
28	1442.4	1455.0	+12.6
29	1446.4	1461.7	+15.3
30	1508.1	1519.8	+11.7
31	1512.9	1524.8	+11.9
32	1530.3	1550.0	+19.7
33	1604.6	1642.1	+37.5
34	1642.2	1684.5	+42.3
35	2223.5	2262.2	+38.7
36	3052.1	3087.4	+35.3
37	3107.9	3158.0	+50.1
38	3137.4	3184.1	+46.7
39	3173.5	3217.0	+43.5
40	3184.9	3228.7	+43.8
41	3198.8	3242.4	+43.7
42	3493.9	3527.6	+33.7

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| 5 cm⁻¹; wb97x max |Δω| 35 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 12:44:02 → 2026-09-28 13:01:05, 1023 s, peak 2.53 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Source files: corpus factory · manifest