The Valence Shell Electron Pair Repulsion model allows the shape of molecules, cations and anions to be simply predicted using the number of bonds and the number of lone pairs on the central atom. It is a powerful model, as long as you know how to first work out the number of bonds and lone pairs by drawing a Lewis structure.

Use this site to:
  1. Study how the geometries depend on the number of electron domains, where
    number of electron domains = number of bonds + number of lone pairs
  2. Investigate these shapes by looking at the possible geometries by molecular formula