Read infrared, ¹H and ¹³C NMR and UV-Vis spectra against a 3D molecule: click a peak and the atoms behind it light up, the molecule vibrates in that mode, or the orbital that absorbs is drawn on it. Built with SceneryStack; runs offline as a Progressive Web App.
- Infrared. 34 molecules with B3LYP/def2-SVP Hessians computed for this sim. The browser runs the normal-mode analysis itself, so isotope substitution (a D₂O shake, all H → D, ¹³C, ¹⁸O, ³⁷Cl) recomputes the spectrum live. Click a band to animate its mode; functional-group regions, normal-mode sticks, line width, and transmittance or absorbance (Preferences). For HCl, a high-resolution view shows the rotation–vibration fine structure: P and R branches with no Q branch, a temperature slider that moves the envelope, and the H³⁷Cl partner of every line.
- ¹H NMR. Equivalent protons from the molecular graph, chemical shifts from additivity rules, exact second-order line positions and intensities from the spin Hamiltonian (or the first-order n + 1 rule for comparison), integration, a D₂O shake, and a spectrometer slider (60–600 MHz) with a zoom that shows roofing at low field giving way to clean multiplets.
- ¹³C NMR. One line per kind of carbon, additivity shifts, and ¹H-decoupled, DEPT-135, DEPT-90 and ¹H-coupled spectra.
- UV-Vis. Hückel and particle-in-a-box (Kuhn) models for polyenes, acenes and cyanine dyes: energy-level diagram, π orbitals drawn as lobes on the molecule, predicted vs measured λmax, and the colour each would give in white light. A Beer–Lambert mode sets concentration and path length, puts the spectrum on an absolute scale, and plots a calibration line that bends over where stray light saturates the spectrometer.
- Unknowns. Identify an isomer from its formula, degree of unsaturation, molecular-ion cluster, IR and ¹H or ¹³C NMR spectra, over three levels.
- Accessible: keyboard operation throughout (rotate the molecule, step through atoms, peaks, signals and orbitals, each announced), live screen summaries, keyboard-help dialogs.
- English, French and Spanish; default and projector colour profiles; installable PWA.
npm install
npm start # dev server → http://localhost:5173Molecule data is committed; regenerating it is optional and needs Python 3:
python3 -I scripts/qm/fetch_structures.py # PubChem 3D conformers → scripts/qm/structures/
python3 -I scripts/qm/export_geometry.py # geometry-only library files (NMR, UV-Vis)
python3 -m venv scripts/qm/.venv && scripts/qm/.venv/bin/pip install -r scripts/qm/requirements.txt
scripts/qm/.venv/bin/python -I scripts/qm/compute_vibrations.py # B3LYP Hessians (hours)| Command | Description |
|---|---|
npm start / npm run dev |
Start Vite dev server |
npm run build |
Type-check + production build → dist/ |
npm run preview |
Preview the production build locally |
npm test |
Run Vitest unit tests (includes memory-leak suite) |
npm run test:fuzz |
Optional Playwright fuzz smoke: pointer (?fuzz) + keyboard (?fuzzBoard), with ?ea, 30s each |
npm run test:fuzz -- 90 |
Same fuzz for 90 seconds (--duration 90 or FUZZ_DURATION=90 also work) |
npm run test:fuzz:quick |
Shorter fuzz smoke (10s) |
npm run test:fuzz:long |
Longer fuzz smoke (300s) |
npm run check |
TypeScript type check |
npm run lint |
Biome lint check |
npm run format |
Auto-format all files |
npm run fix |
Lint + auto-fix |
npm run icons |
Regenerate PNG icons from public/icons/icon.svg |
npm run release |
check && lint && build && test, then version patch + push tags |
npm run clean |
Remove dist/ |
New sims start at version: "0.0.0" in package.json. Bump only when cutting a release (for example npm version patch and a matching git tag). Keep name in kebab-case; it is separate from the SceneryStack sim identifier in src/init.ts, which reads its version from package.json.
| Tool | Version | Purpose |
|---|---|---|
| SceneryStack | ^3.0.0 | Simulation framework |
| Vite | ^8 | Build tool + dev server |
| TypeScript | ^7 | Type-safe JavaScript |
| Biome | ^2.5 | Linting + formatting |
| vite-plugin-pwa | ^2 | PWA + service worker |
| PySCF + geomeTRIC | 2.14 / 1.1 | Offline B3LYP Hessians (dev-only, scripts/qm/) |
GNU Affero General Public License v3.0 — see OpenLyceum org license.
See OpenLyceum contributing guidelines. Report bugs via GitHub Issues; use org issue templates.