Calculations of Solid Properties Using Wien2k Package
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Structures of Metals: Close Packing.

Go down

Structures of Metals: Close Packing. Empty Structures of Metals: Close Packing.

Post by Algerien1970 Wed 20 May - 15:59

Metallic Bonding in the Solid State:

For metals the atoms have low electronegativities; therefore the electrons are delocalized over all the atoms.  We can think of the structure of a metal as an arrangement of positive atom cores in a sea of electrons. For a more detailed picture see "Conductivity of Solids".

Structures of Metals: Close Packing. Seaelectrons


To maximize the bonding in a metal it makes sense to pack as many atoms around each other as possible, maximize the number of nearest neighbors (called the "coordination number") and  minimize the volume.

Close packed layers of atoms.

If we treat the atoms as spheres and consider all the atoms in the solid to be of equal size (as is the case for elemental metals), the most efficient form of packing is the close packed layer.  This is illustrated below where it is clear that close-packing of spheres is more efficient than, for example, square packing.

Below on the left is a square packed array compared to the more densely packed close packed array.
Within the square packed layer the coordination # of each atom is 4, in the close packed layer it is 6.

Structures of Metals: Close Packing. Squareclose    

to continue reading clik on the link below


[You must be registered and logged in to see this link.]
Algerien1970
Algerien1970
Forum Manager
Forum Manager

Messages : 485
Date d'inscription : 2015-05-14

https://wien2k.forumalgerie.net

Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum