[Pw_forum] graphene's band gap

[xirainbow]

Dear Eric:
The occupied and unoccupied bands touch each other only at M point(or K
point, I forget it).
You must include this point in you k-mesh.
Furthermore, if you include spin-orbital coupling, the band gap will be
opened at this point.

On Thu, Mar 10, 2011 at 1:30 AM, Eric Germaneau <germaneau at gucas.ac.cn>wrote:

>  Dear all,
>
> I'm trying to compute graphene's band gap but get stuck.
> From my understanding a scf calculation should provide the same energy for
> the highest occupied and lowest occupied level which means a zero gap.
> I played with the number a kpoints a finally got a band gap of 0.57 which
> is not null.
> The scf convergence looks good.
> I'm not (yet) an expert in DFT calculation so may did something wrong or
> misunderstood something here.
> So, I wonder if someone has already successfully performed such
> calculation.
> I have attached my input file.
> Thanks in advance,
>
>                                 Eric.
>
> --
>  * Be the change you wish to see in the world
> *  — Mahatma Gandhi —
>
> Dr. Éric Germaneau <germaneau at gucas.ac.cn>
>
> College of Physical Sciences
> Graduate University of Chinese Academy of Sciences
> Yuquan Road 19A
> Beijing 100049
> China
>
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-- 
____________________________________
Hui Wang
School of physics, Fudan University, Shanghai, China
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