[Pw_forum] band structure of graphene-size effect of unit cell

[Gabriele Sclauzero]

Dear Loc Duong Dinh,

   have you haver heard about "refolding" of the band structure (in the context of supercells)? If not, first have a look at some good electronic structure textbook. 
The band structure is actually the same, but in practice you are visualizing it in a different way. Try to compute the (fully converged) DOS for the two different unit cells and compare them (with appropriate weights). What do you see?


GS

Il giorno 22/lug/2010, alle ore 05.16, loc duong ding ha scritto:

> Dear all,
> 
> I have a problem when I calculate band structure of graphene. The band structure 
> of graphene calculated by unit of 2 atoms and 8 atoms is different. the gap at 
> gama point as well as M point are totally different. 
> 
> 
> In general case, unit of 2 atoms and unit of 8 atoms both create graphene 
> strucutre. I can not unserstand why they are different? Is my understanding is 
> wrong? 
> 
> 
> I know this is the general question but I hope I can receive helpful 
> instructions. 
> 
> 
> I aprreciate all ypur helps. 
>  
> Sincerely,-----------------------------------------------
> Loc Duong Dinh
> Ms-Ph.D Student
> Sungkyunkwan Advanced Institute of Nanotechnology,
> Sungkyunkwan University,
> Suwon, 440-746, Korea 
> Email: mambom1902 at yahoo.com, ddloc at skku.edu 
> 
> 
> 
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§ Gabriele Sclauzero, EPFL SB ITP CSEA
   PH H2 462, Station 3, CH-1015 Lausanne

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