[Wien] Reg: Supercell calculation

[pieper]

Dear Swetha Gummula,

The physical properties of a material do not depend on wether or not you 
make use of symmetry properties when you calculate them. This is true 
also if you use Wien2k for your calculations - with the caveat that you 
should be careful to converge the scf to the same degree with respect to 
calculation parameters like RMT's and k-mesh.

You might want to estimate the influence of symmetries on convergence. 
You know best which physical properties you are interested in: calculate 
them for your 'normal', undoped Heusler system, using the full symmetry. 
Then create your supercell where you split e.g. a symmetry equivalent Fe 
position into Fe1 and Fe2. This breaks some symmetries, meaning that 
Wien2k will not use them, but the material described by case.struct 
stays the same. Don't change the RMT's, you probably can reduce the 
number of k-points. When you calculate the physical properties the 
results should be the same.

You are right, however, it is safer to compare only calculations which 
used the same symmetry. Use the splitting of Fe- or other positions to 
generate a supercell case.struct describing your undoped Heusler alloy 
using the lowest symmetry you have for your doped systems. Create a new 
case and copy the .struct from the reference case. Dope this by changing 
one Fe into whatever. Then do all calculations in the reference case and 
the doped one with equal parameters (RMT's, k-mesh ...).


Am 12.11.2013 17:21, schrieb Shwetha Gummula:
> Dear wien2k users and developers,
> 
>                       I am working on Heusler
> alloys, i am trying to create the supercell then dope with some
> element. I created 2x2x2 supercell, then it is lowering the symmetry
> and changing the space group (giving the lattice type P, B..). Is it
> possible to be in that spacegroup and create supercell??.
> 
> When we will create the supercell  it changes the  symmetry, so my
> doubt is  how to compare the original structure with the supercell
> structure where the spacegroup is different.
>  Thanking you
> 
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