# Graphite

Choose one of the options below, based on which program you want to view the structure with.

For viewing with the demo version of CrystalMaker
Go to Graphite at Stephen Heyes' website at Oxford University and click on the word "Graphite" to download and open in CrystalMaker for viewing, or...

Download the graphite structure as graphite unit cell ( 8kB Jun8 07). These are cmdf files which you can view in CrystalMaker or...

Download the graphite structure in pdb format (courtesy of WebElements.com). This can be imported into CrystalMaker.
For viewing with the commercial version of CrystalMaker
Open the Crystal Structures Library on the CrystalMaker disc, and click on Minerals > Non-Silicates > Native Elements > Carbon-graphite.
For viewing with XtalDraw
Click on the GRAPHITE file in the XtalDraw folder.

## Questions

Before proceeding, choose the Model -> Ball and Stick rendering option to better see where the C atoms are located in the structure.
1. Consider only the bonding within a single horizontal plane. What is the coordination number for each C atom within this plane?
2. The CN is 3.
3. What is the bond angle between an C atom and its two nearest neighbors in the horizontal planes?
4. View the structure down the c-axis (perpendicular to a plane of carbon atoms). If you rotate it 30, 45, 60, 90, 120, or 180° about the center of a ring of C atoms, does it remain the same?
5. For rotation about the center of a C ring, the structure repeats itself every 60, 120, and 180°.
6. Now try a rotation centered on any C atom. If you rotate it 30, 45, 60, 90, 120, or 180° about any C atom, does it remain the same?
7. For rotation about a C atom, the structure repeats itself every 120°.
8. Does the structure have any mirror planes? You may have to add more atoms to the structure to evaluate this: Transform -> Set Range.
9. How does the structure of graphite control its hardness and cleavage?