[Wien] supercell

[Mojtaba Zareii]

Hi dear users

I want to investigate electronic and magnetic structure of
Co2FeAl(1-x)Si(x) heusler compounds.

I could execute Co2FeAl (x=0) and Co2FeSi (x=1) compounds crystallized
in the cubic L21(space group Fm3m , number 225) where the atoms are
placed on following positions:
Co (8c) : (0.25,0.25,0.25)
Fe  (4a) : (0,0,0)
Al   (4b): (0.5,0.5,0.5)
[ Lattice parameter (for Co2FeAl) is a=b=c=5.733A ]

Up here it is straightforward and easy, but in the next stage I  faced
a problem when  I wanted to simulate Co2FeAl(0.75)Si(0.25) compound (
for x=0.25) that it is required  to create a supercell, but I don't
know how such a supercell should be created.

Could you please help me with this problem?
Thank you very much.

S.M.Zareii
Ph.D student in condensed matter physics