benzene+CH3+Cl C7H7Cl

B_0550b7e251 · SMILES Cc1ccc(Cl)cc1 · InChIKey NPDACUSDTOMAMK-UHFFFAOYSA-N

Cheap level done imaginary mode, second route pending

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)

39 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	29.7	-46.9	-76.5
2	119.2	130.4	+11.2
3	249.9	255.5	+5.6
4	303.6	317.8	+14.2
5	374.7	378.6	+3.9
6	378.9	382.7	+3.8
7	420.7	431.8	+11.1
8	496.9	509.6	+12.7
9	635.3	643.1	+7.9
10	650.2	654.0	+3.8
11	707.0	726.8	+19.8
12	812.1	823.4	+11.3
13	821.7	838.0	+16.3
14	840.3	860.1	+19.8
15	956.0	979.0	+23.0
16	960.7	992.8	+32.1
17	1019.4	1021.0	+1.6
18	1032.5	1039.7	+7.3
19	1076.5	1083.3	+6.8
20	1111.5	1128.8	+17.3
21	1144.8	1141.4	-3.4
22	1214.3	1212.2	-2.2
23	1239.2	1255.0	+15.8
24	1333.9	1298.2	-35.7
25	1343.8	1338.5	-5.3
26	1444.4	1453.5	+9.1
27	1446.6	1459.0	+12.4
28	1518.3	1521.3	+2.9
29	1522.3	1528.7	+6.3
30	1542.3	1558.5	+16.1
31	1632.0	1666.6	+34.7
32	1657.8	1696.8	+39.0
33	3042.1	3078.1	+36.0
34	3099.7	3148.6	+48.9
35	3126.7	3174.2	+47.5
36	3183.8	3227.4	+43.6
37	3184.5	3228.0	+43.5
38	3221.1	3263.7	+42.5
39	3222.2	3264.7	+42.6

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-25, 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.

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 2 cm⁻¹; wb97x max |Δω| 120 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, 2026-09-25 18:04:34 → 2026-09-25 18:17:33, 778 s, peak 2.26 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 1
Source files: corpus factory · manifest