[Wien] band structure for clusters

[Rocquefelte]

Dear Souraya,

After a brief discussion with my colleague Florent Boucher, I would like 
to add just one more comment. If you consider the whole cluster in one 
unit cell, and use a supercell approach in Wien (in such a way to have 
no cluster interaction), you will need only one k point to describe the 
system, whatever is the size of your cluster.

Regards

Xavier

Rocquefelte a écrit :

> Dear Souraya,
>
> If you have a very small cluster, then you will have no periodicity. 
> The k-space allows to describe the effect of the periodicity on the 
> energy of the system and then its properties.
> A small cluster is like a molecule. You will have no energy 
> dispersion, only discrete levels.
> If you now progressively increase the size of your cluster you will 
> see more and more energy levels in your diagram (because you will have 
> more atoms), and this will finally lead to a continuum of energy 
> levels (band dispersion).
> To conclude, the answer to your question is clearly dependent of the 
> size of your cluster. But for very small cluster the answer is clearly 
> yes, the band structure will be flat.
>
> Best Regards
>
> Xavier
>
> Souraya GOUMRI-SAID a écrit :
>
>> Dear User Wien2K,
>>
>> Is it true that the band structure should be flat for small cluster ?
>>
>> If yes, can you please give the arguments.
>>
>> Sincerely yours,
>>
>>
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>>
>
>


-- 
Xavier Rocquefelte
Maître de Conférence de l'Université de Nantes

Institut des Matériaux Jean Rouxel (IMN)
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