naphthalene+CH3+ethynyl C13H10

B_616dcfa1ff · SMILES C#Cc1cccc2cc(C)ccc12 · InChIKey LOVDJSDJBCGUNQ-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.

Infrared spectrum at the cheap level (B3LYP/6-31G*, the pipeline's input)

cheap input (B3LYP) bands

How to read this

47 infrared-active bands (500–3500 cm⁻¹); the strongest at 3494 cm⁻¹ (2.9 µm), 86 km/mol.

cheap input (B3LYP): blue curve, sticks orange at the curve's peak scale. Lorentzian, FWHM 10 cm⁻¹; axis in km mol⁻¹ per cm⁻¹.

Band heights from the molecule's dipole derivatives and the same B3LYP Hessian as the listed positions (double harmonic).

Predicted spectrum (rung 3, the learned correction): computed by the pipeline, not drawn on this page; licensed for ring-ip, CH-stretch, CH-oop (decision 65).

How well is this shape known?

measured on (ΔH network v1.3)	spectrum overlap cheap → corrected	height error cheap → corrected
8 unseen simple aromatics (layer A), DFT stand-in for the higher level	0.28 → 0.98	0.23 → 0.10
31 molecules of unseen scaffolds, DFT stand-in for the higher level	0.37 → 0.97	0.51 → 0.24
against coupled cluster	not measured for this version

Overlap: similarity of the two broadened spectra (1 = the same shape). Height error: relative error per band, weighted by height (0 = the same heights). "Corrected" is the learned correction on molecules it never saw; the pipeline serves it for the licensed families. Open: the dipole derivatives themselves are computed at the cheap level (on benzene they differ from coupled cluster by about 20 %).

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-30, ubuntu-32gb-hel1-18
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.

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

63 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP; height = B3LYP band height (km/mol).

The B3LYP bands are drawn in the spectrum above; the table adds their heights, the ωB97X positions and the shift.

#	B3LYP (cm⁻¹)	height (km/mol)	ωB97X (cm⁻¹)	shift
1	89.3	0.82	67.8	-21.5
2	94.1	0.00	109.0	+14.9
3	134.0	0.32	148.9	+15.0
4	134.9	0.28	153.0	+18.1
5	203.6	1.81	215.3	+11.7
6	266.6	0.46	273.9	+7.3
7	282.8	0.20	292.6	+9.7
8	379.5	2.81	389.4	+9.9
9	381.9	0.64	400.0	+18.1
10	448.8	0.46	452.6	+3.8
11	456.5	1.97	461.1	+4.6
12	461.1	3.45	473.0	+11.9
13	508.2	2.28	517.5	+9.2
14	549.7	43.91	558.8	+9.0
15	553.0	0.54	596.4	+43.4
16	587.3	0.51	623.8	+36.5
17	611.0	1.72	644.6	+33.6
18	630.6	41.34	669.2	+38.6
19	658.1	2.73	691.6	+33.5
20	703.5	0.02	709.6	+6.1
21	724.8	2.35	729.5	+4.8
22	765.6	7.91	779.5	+13.9
23	815.3	21.80	832.1	+16.8
24	842.7	27.72	853.9	+11.1
25	846.6	2.09	855.4	+8.8
26	895.5	8.64	917.8	+22.2
27	923.4	0.49	950.5	+27.2
28	948.7	0.56	959.4	+10.7
29	976.1	1.02	1007.0	+30.9
30	977.4	0.11	1009.3	+31.9
31	1035.4	7.55	1036.9	+1.6
32	1045.1	2.59	1052.7	+7.6
33	1077.1	4.51	1084.4	+7.3
34	1104.6	2.11	1115.0	+10.4
35	1190.7	1.89	1189.8	-0.9
36	1200.4	0.79	1195.5	-4.9
37	1207.8	1.49	1209.9	+2.1
38	1250.0	2.81	1243.3	-6.6
39	1269.5	0.12	1280.4	+10.8
40	1303.1	3.74	1313.0	+9.9
41	1377.7	3.62	1370.2	-7.5
42	1408.4	1.50	1418.9	+10.5
43	1415.5	5.45	1422.4	+6.8
44	1443.4	0.21	1453.1	+9.8
45	1472.6	7.72	1487.2	+14.6
46	1508.7	2.15	1514.2	+5.5
47	1513.2	5.71	1521.8	+8.6
48	1525.3	3.57	1537.8	+12.5
49	1557.8	11.63	1587.9	+30.0
50	1627.9	0.73	1664.7	+36.9
51	1645.4	7.40	1674.0	+28.7
52	1686.2	10.36	1729.2	+43.0
53	2217.6	3.12	2255.3	+37.7
54	3040.8	38.12	3076.1	+35.3
55	3091.1	20.44	3141.7	+50.5
56	3126.6	15.86	3173.6	+47.0
57	3172.5	15.96	3217.3	+44.8
58	3178.5	14.52	3222.2	+43.7
59	3182.2	5.64	3225.6	+43.4
60	3199.8	22.38	3242.8	+42.9
61	3213.1	10.54	3256.7	+43.7
62	3215.9	13.12	3258.6	+42.7
63	3494.4	85.61	3529.2	+34.8

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 3 cm⁻¹; wb97x max |Δω| 33 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-hel1-18, 2026-09-30 08:15:28 → 2026-09-30 09:08:52, 3203 s, peak 4.3 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Cheap-level band heights: dipole derivatives dipole_b3lyp_cphf.npz, Hessian hessian_b3lyp.npz
Source files: corpus factory · manifest