[Pw_forum] number of bands and degenerate states in supercell

[Duy Le]

The logic is simple:
#bands = #electrons/2+#unoccupied_bands
If you increase the size of unit cell, #atoms increase as well, so do #electrons
However, you will have something called band folding because the BZ shrinks.
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Duy Le
PhD Student
Department of Physics
University of Central Florida.

"Men don't need hand to do things"



On Fri, Mar 11, 2011 at 1:37 PM, pari shok <parishok at gmail.com> wrote:
> Hello,
> I have a question and I appreciate your help in advance.
> I am making a supercell by repeating a unit cell of SiC. Then, instead of 8
> atom in a hexagonal structure, there are 72 atoms in a supercell.
> My question is about the number of bands.
> Theoretically, the number of bands would be just the same for the unit cell
> (32 in this case) and even if you increase them in the input file, they
> should just have degeneracy and overlap. However, they are not.
> I was wondering how I can interpret the bands.
> Yours
> P Shok
> UMD
>
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