[Wien] Supercell

[Stefaan Cottenier]

>  But I don't know  what should I do for calculating band structure of
> Al(x)Ga(1-x)N alloy with an arbitrary x,for example replacing one Ga 
> with Al atom,....what is the key point in replacing of atoms,i.e. 
> which Ga shoud be replaced with Al atom.

Any one is good. Then do init_lapw again and accept changes by nn and 
sgroup.

Note: if you replace a Ga in the file you sent, then you will replace 
2 atoms (all have multiplicity 2), hence x=2/16. If you really want 
x=1/16, you need to split one of the Ga atoms in 2 inequivalent 
positions, each with multiplicity 1, and replace then one of those by 
Al.

Stefaan