Chembook - Reaction Visualizer

Chembook is an offline chemistry reference built around things you can turn, step through, and take apart.

REACTION MECHANISMS IN 3D Step through 128 reaction mechanisms frame by frame, with curved electron-pushing arrows drawn on the actual atoms. Explore quantum-optimized structures alongside teaching models of the steps between them. Switch between the 3D model and a clean 2D skeletal depiction.

ADVANCED TOPICS Explore six interactive lessons: collision theory, potential energy surfaces, Woodward–Hoffmann rules, crystal field and Jahn–Teller effects, Walsh diagrams, and band theory. Follow reaction trajectories across energy landscapes. Change molecular geometry to see orbital energies shift, explore spin and distortion, and watch discrete energy levels become bands.

ATOMIC & MOLECULAR ORBITALS Rotate orbital isosurfaces in 3D, from s, p, d and f atomic orbitals to computed molecular orbitals. Explore their shapes, nodes and wavefunction signs.

SPECTROSCOPY REFERENCE 1H and 13C NMR shift tables, IR and Raman bands, mass spectrometry and UV-Vis, with tappable reference entries that place peaks on a live spectrum. Includes an interactive n+1 splitting-tree tool.

MOLECULAR DYNAMICS LAB Run interactive molecular simulations on your device. Explore argon, water and ionic systems, adjust temperature and density, and watch molecular motion and the radial distribution function update as the simulation runs.

STRUCTURES & CONFORMERS Chair flips, anomers, amino acids, unit cells and framework solids in 3D, with a Ramachandran plot and potential-energy scans you can drag.

PERIODIC TABLE All 118 elements with trends, a comparison view and detailed properties.

QUIZ Seven modes: periodic table, compound hunt, reaction mechanisms, spectra identification, vibrational mode matching, nomenclature, and amino acids.

BUILT FOR OFFLINE STUDY All reference content, lessons and visualizations work offline. No Chembook account, no sign-in, no analytics, no ads and no personal data collection. Your notes and study progress stay on your device. An internet connection is needed for purchases and restores.

FREE AND PRO 20 core reaction mechanisms, the full periodic table, all spectroscopy reference, orbitals, structures, and the molecular dynamics lab are free. A single one-time purchase unlocks the remaining 108 mechanisms, all six Advanced Topics lessons and unlimited quiz play.