ODYSSEY Resonance app for iPhone and iPad

How different are double and triple bonds from single bonds? And what do double-bonded molecules with multiple Lewis structures―such as ozone, nitric acid, and benzene―look like?

ODYSSEY Multiple Bonds and Resonance is a visualization app that uses the results of rigorous quantum chemical calculations in order to fight pervasive misconceptions about molecular structure. Models of 51 simple molecules and ions are provided, both inorganic and organic. Each model can be manipulated in 3D with simple gestures. Bond lengths and bond angles can be queried.

The user can pick from conventional model styles such as Ball&Spoke and Space Filling. Surpassing schematic representations, the electron clouds can also be displayed as isosurfaces of the electron density. A table of standard bond lengths, glossary, comments section, and a set of multiple-choice questions (with randomized options) complete the app.

Resonance is a core concept of chemistry that is surrounded by mystery. Working with ODYSSEY Multiple Bonds and Resonance and taking an inquiry-based approach can help provide a clearer understanding of the subject.