Teaching Mineralogy with Crystal Structure Databases and Visualization Software
Integrating Research and Education > Crystallography > Directed Discovery of Crystal Structures > Crystal Structures > Halite

Halite

Download the structure for interactive viewing

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 (more info) ,
Go to NaCl Rock Salt (Halite) at Stephen Heyes' website at Oxford University and click on the image of the halite crystal structure to download and open in CrystalMaker for viewing, or...

Go to the Extended Structures Libraries on the CrystalMaker website, and download the "Additional Phases" archive. Within the resulting folder "Appendix", click on the file named "NaCl, Halite (B1,Fm3m)" which will open automatically in CrystalMaker, or...

Download the halite structure as halite unit cell ( 2kB Jun8 07). This is a cmdf file which you can view with CrystalMaker.
For viewing with the commercial version of CrystalMaker (more info) ,
Open the Crystal Structures Library on the CrystalMaker disc, and click on Minerals > Non-Silicates > Halides > Halite-NaCl.
For viewing with XtalDraw (more info) ,
Click on the HALITE file in the XtalDraw folder.



Questions

  1. In halite, which element is the cation? Which element is the anion?
  2. Na is the cation, and Cl is the anion.
  3. What type of bonding occurs between the cations and anions in halite?
  4. What is the coordination number of Na?
  5. Consider a single cation and the anions it is bonded to. If you connect the anions, what type of polyhedron forms around the cations?
  6. How many cleavages occur in NaCl? What is the angle between them?
  7. Look down a single row of atoms that are perpendicular to one of the flat faces. What is the rotational symmetry in this direction?
  8. 4-fold
  9. Rotate so you are looking down the main diagonal fo the cube. (From corner to opposite corner.) What is the symmetry in this direction? (ignore rotoinversion for now and just treat as a simple rotation)
  10. 3-fold rotation
  11. This structure contains 2-fold, 4-fold and 3-fold rotation axes. How many identical 2-fold axes are there? How many identical 4-fold axes are there? (Warning: counting these rotational axes is quite difficult for the computer visualization)
  12. How many sets of mirror planes occur in this structure, and what is the angular relation between these planes?

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