[Wien] How to construct a supercell?

[Stefaan Cottenier]

>    I am engaged in constructing a supercell,but I do not know to how
> to create it,for example FeSi(2-x)Al(x).What references I should
> read?Who would like to help me?Thank you in advance. 

1) create a single FeSi unit cell
2) enlarge it to e.g. 2x2x2 by 'x supercell' (see UG)
3) replace a few Si by Al (you will see that not all values of x are 
possible, due to the limited number of atoms in the supercell. With 
3x3x3 you can simulate more values, but the calculations are much 
longer).

Stefaan