[Wien] structure confusion ?

[Rocquefelte]

Don't forget that border atoms are shared with other cells !
Thus for Mg atoms you have:
- 8 Mg at the corners - each shared between 8 cells -> 8/8 =1 Mg in 1 cell
- 6 Mg at the center of the faces - each shared by 2 cells -> 6/2 = 3 Mg 
in 1 cell
- 4 Mg inside the cell

Thus you have 8/8 + 6/2 + 4 = 8 Mg atoms in one cell.

Regards

Xavier




Le 4/30/2013 6:22 AM, Zaid a écrit :
> Respected Community
>
> I have a little confusion in understanding the spinel structure. I am 
> attaching a perfect MgAl2O4 spinel structure. Why this structure shows 
> more than 8 Mg (Yellow in colour) elements ? There should be 8 Mg, 16 
> Al and 32 O atoms that adds up to give 56 atoms. I also see more no of 
> atoms in Xcrysden.
>
> Best wishes
> Zaid
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20130430/c2720657/attachment.htm>