[Pw_forum] Defining an antiferromagnetic graphene nanoribbon

[Stefano Baroni]

The kinetic-energy cutoff is a property of the atomic core, NOT of the  
specific system (to a large extent).
SB

On May 10, 2008, at 6:11 PM, Roberto G. A. Veiga wrote:

> Dear Stefano:
>
> I'm using Ultrasoft PPs. My question was because this cutoff (20 Ry)  
> seemed to be appropriate for other carbonic systems.
>
> []s,
>
> Roberto
>
> Stefano Baroni <baroni at sissa.it> wrote:
>
> On May 9, 2008, at 10:42 PM, Roberto G. A. Veiga wrote:
>
>> Hi, Konstantin:
>>
>> thank you very much. Such a large cutoff (80 Ry) is necessary for  
>> convergence? Or maybe I'm using one quite small (20 Ry)...
>
> it depends on the PP you are using, I guess, and certainly NOT on  
> the actual structure you are studying. 80 Ry seems like an  
> appropriate cutoff for moderately hard norm-conserving PP's, whereas  
> 20 Ry sounds like appriate for many US PP's. In either case, you  
> better check the aprporiateness by yourself, through thorough  
> convergence tests.
>
> Stefano
>
>
>>
>>
>> []s,
>>
>> Roberto
>>
>> Konstantin Kudin <konstantin_kudin at yahoo.com> wrote:
>> Hi Roberto,
>>
>> Here is a ribbon input that works for sure:
>> https://kiev.princeton.edu/misc/rg_07.scf.in
>> (get PPs from the PWSCF website)
>>
>> Good luck!
>> Kostya
>
> ---
> Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
> Trieste
> [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)
>
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---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
Trieste
[+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)

La morale est une logique de l'action comme la logique est une morale  
de la pensée - Jean Piaget

Please, if possible, don't  send me MS Word or PowerPoint attachments
Why? See:  http://www.gnu.org/philosophy/no-word-attachments.html





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