naphthalene+OCH3+OCH3 C12H12O2

B_1a48fabe9a · SMILES COc1cc(OC)c2ccccc2c1 · InChIKey XAVOEDQPSYWNHI-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

51 infrared-active bands (500–3500 cm⁻¹); the strongest at 1684 cm⁻¹ (5.9 µm), 146 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 — 2026-09-28, ubuntu-32gb-hel1-18
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

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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.

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

72 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	79.5	6.52	102.6	+23.0
2	86.0	1.02	116.2	+30.3
3	122.0	0.01	149.6	+27.6
4	175.2	0.38	189.6	+14.4
5	184.6	2.43	195.6	+11.0
6	208.6	1.33	218.1	+9.5
7	213.9	1.30	243.2	+29.3
8	244.4	0.00	275.1	+30.6
9	284.7	1.26	317.7	+32.9
10	325.7	0.26	338.2	+12.5
11	330.6	1.12	339.0	+8.4
12	395.2	4.94	400.1	+4.9
13	444.8	1.48	452.5	+7.7
14	459.5	6.86	465.4	+5.9
15	512.4	2.80	519.4	+6.9
16	538.2	3.74	547.0	+8.8
17	541.9	1.15	549.2	+7.3
18	631.4	1.14	636.0	+4.6
19	635.6	4.64	650.9	+15.3
20	652.5	0.15	665.1	+12.7
21	664.9	16.78	671.1	+6.3
22	760.0	16.14	770.4	+10.4
23	779.5	0.64	786.1	+6.5
24	782.0	4.75	795.3	+13.3
25	823.1	17.84	838.5	+15.4
26	840.9	54.52	854.3	+13.4
27	879.5	2.17	896.4	+16.9
28	898.5	0.27	906.4	+7.9
29	954.8	1.56	984.0	+29.3
30	971.8	16.59	985.5	+13.7
31	985.0	0.01	1015.2	+30.2
32	1025.4	4.92	1037.8	+12.4
33	1058.4	9.58	1067.3	+8.8
34	1091.1	38.15	1105.6	+14.5
35	1145.7	50.69	1153.0	+7.4
36	1182.1	20.79	1174.1	-8.0
37	1185.5	0.24	1196.8	+11.4
38	1185.9	1.51	1198.0	+12.1
39	1195.7	50.48	1202.6	+6.9
40	1203.8	109.13	1210.5	+6.7
41	1226.3	8.17	1230.5	+4.3
42	1237.0	105.35	1240.3	+3.2
43	1259.7	132.53	1265.0	+5.3
44	1277.2	39.41	1275.9	-1.3
45	1329.5	99.59	1328.7	-0.8
46	1391.9	30.42	1393.6	+1.6
47	1416.6	17.42	1424.9	+8.3
48	1455.1	128.71	1460.7	+5.6
49	1481.9	23.39	1494.5	+12.6
50	1487.2	35.53	1497.8	+10.6
51	1510.1	15.99	1523.0	+12.9
52	1518.0	24.64	1529.9	+12.0
53	1518.4	5.78	1532.4	+14.0
54	1519.3	6.07	1533.4	+14.1
55	1536.0	26.20	1547.0	+11.0
56	1536.5	19.65	1548.3	+11.8
57	1566.0	26.90	1593.5	+27.6
58	1638.0	69.13	1669.4	+31.5
59	1660.2	112.45	1686.1	+25.9
60	1683.9	145.81	1727.7	+43.8
61	3026.3	54.25	3062.6	+36.2
62	3029.1	53.73	3065.3	+36.3
63	3085.0	41.22	3133.5	+48.5
64	3089.4	41.29	3137.9	+48.5
65	3156.2	30.17	3199.4	+43.2
66	3158.5	23.19	3201.8	+43.3
67	3175.1	2.75	3218.9	+43.8
68	3188.7	19.49	3232.3	+43.6
69	3202.3	33.17	3245.6	+43.2
70	3222.4	12.02	3267.5	+45.0
71	3227.6	9.82	3271.7	+44.1
72	3242.3	4.35	3286.9	+44.6

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 24 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, 2026-09-28 03:55:02 → 2026-09-28 05:07:35, 4352 s, peak 5.2 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