The VSEPR theory (valence shell electron pair repulsion theory) shape of molecules depicts Lewis electron dot structures as 3 dimensional arrangements of atoms. Further, VSEPR theory predicts the shape or geometry of most polyatomic molecules.

Both styles of Indigo® VSEPR theory molecular models are particularly versatile for illustrating this. They both include molecular orbitals to depict nonbinding electrons. The Orbit style allows accurate purine & pyrimidine ring structures to be built in our 12 base pair DNA model using carbon with 3 different bond angles and nitrogen with two.

The Unit style is even more versatile in being able to depict subtle orbital interactions that determine the many molecular shapes found in organic chemistry and biochemistry. Atoms positioned in the axial position can be combined with other atoms in the many available equatorial positions to depict virtually any hydrogen, ionic or covalent bonded molecules. (See Unit Style-More Information).