Chembook - Reaction Visualizer

90 reaction mechanisms you can step through in 3D, plus orbitals, NMR/IR reference, a live molecular dynamics lab and five quiz modes. Works fully offline.

Chembook is an offline chemistry reference built around things you can turn, step through, and take apart — not static diagrams.

REACTION MECHANISMS IN 3D Step through 90 named organic mechanisms frame by frame. Every structure is a computed geometry, most of them quantum-optimized, with curved electron-pushing arrows drawn on the actual atoms. Switch any reaction between the 3D model and a clean 2D skeletal depiction.

ATOMIC & MOLECULAR ORBITALS Real computed orbital isosurfaces you can rotate — s, p, d and f atomic orbitals through to molecular orbitals, rendered from volumetric data rather than illustrations.

SPECTROSCOPY REFERENCE 1H and 13C NMR shift tables, IR and Raman bands, mass spectrometry and UV-Vis, each row tappable to place its peak on a live spectrum. Includes an interactive n+1 splitting-tree tool.

MOLECULAR DYNAMICS LAB A real simulation, not an animation. Watch argon condense, water freeze into an ice lattice and melt again, or salt dissolve in a polar solvent — with temperature and density under your control and the radial distribution function updating as it 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, comparison view and full property detail.

QUIZ Five modes — periodic table, compound hunt, reaction mechanisms, spectra identification and vibrational mode matching.

EVERYTHING WORKS OFFLINE No account, no sign-in, no network connection, no analytics, no ads, no data collection of any kind.

FREE AND PREMIUM 20 core reaction mechanisms, the full periodic table, all spectroscopy reference, orbitals, structures, the molecular dynamics lab and a set of trial quiz rounds are free. A single one-time purchase unlocks the remaining 70 mechanisms and unlimited quiz play. No subscription.