Vsepr Theory Chart

Knowing the geometry of molecules is vital to understand its reactions.  VESPR is a short for Valence Shell Electron Pair Repulsion. It provides a simple method of predicting the geometries of main group compounds. The VESPR theory is applied when predicting the combinations of electron doubles around atoms in simple and symmetric molecules. In them, central atoms attach to two or more other atoms. The shapes of these key atoms and the non-bonding electron doubles influence the shape of the larger whole.

The VESPR Shape Chart available for download consists out of columns and rows. The description each of the columns and their usage is described below:

1. Total domains.This column contains numbers from 1 to 6 (also called "numbers of electron domains" or "steric numbers"). A steric number is usually indicated as SN. To calculate this number, you should sum up X and E that atom A has in a molecule. Electron domains include bonded atoms, lone pairs of electrons, and unpaired electrons. You should consider multiple connections as one electron domain.
2. Generic formula. It reflects the electron pairs circling a central atom. The basic formula is AxnEm, where A is the central atom, X denotes atoms circling A, and E denotes lone pairs of electrons on the A (central atom).
3. A sample picture of electron-group shape represents the appearance of the molecule.
4. Bonded atoms. This column contains the amount of connected atoms. To calculate this number, you should summarize all the X in the generic formula.
5. Lone pairs. This column represents the amount of lone pairs, which is a place with non-bonding electrons. To calculate this number, you should summarize all the E in the generic formula.
6. Molecular shape. Linear,trigonal planar tetrahedral, trigonal bipryamidal, octahedral.
7. Electron geometry. This column contains the general molecular shape and other parameters, such as lengths and angles of bonds that demonstrate the location of each atom.
8. An example of the compound. For example, H2, CO2, AIBR3, SnCI2, O2, PH3, and CI2
9. Hybridization. This column contains hybridization. If you may determine the angles between hybrid orbitals, it will help to explain to you a molecule shape, because these angles are nearly equal to the angles between bonds. There are several types of hybridization: sp, sp2, sp3.
10. Bond angles. A bond angle is a theoretical angle between two adjoining bonds. It differs depending on the shape of the molecule.

More info about the VSEPR theory can be found at Wikipedia