Dear Mohammadreza Hosseini,

are you talking about band folding? I wrote a small utility to unfold
the band structure of supercells long time ago. It's in a git repository
hosted on qe-forge.org (project name is unfold).

Kind regards,
Pietro Bonfa'

On 05/15/2017 11:16 AM, Mohammadreza Hosseini wrote:
> 
> 
> ________________________________________
> From: Mohammadreza Hosseini
> Sent: Sunday, May 14, 2017 1:43 AM
> To: [email protected]
> Subject: Re: Pw_forum Digest, Vol 118, Issue 12
> 
> Dear All
> 
> I am calculating the band structure of phagraphyne. First we computed for 
> primitive unit cell and then for the 2X2 supercell. Although the bulk 
> structure is same the band structure is different. What is the problem ?  
> Should parameters be optimized again for supercell?
> 
> Mohammadreza Hosseini
> Tarbiat modares uiversity
> ________________________________________
> From: [email protected] <[email protected]> on behalf of 
> [email protected] <[email protected]>
> Sent: Saturday, May 13, 2017 10:00 PM
> To: [email protected]
> Subject: Pw_forum Digest, Vol 118, Issue 12
> 
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> Today's Topics:
> 
>    1. Re: how to determine the symmetry of a given phonon mode  in
>       quantum espresso (Lorenzo Paulatto)
>    2. Re: Gipaw - Magnetic susceptibility (Davide Ceresoli)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sat, 13 May 2017 15:08:04 +0200
> From: Lorenzo Paulatto <[email protected]>
> Subject: Re: [Pw_forum] how to determine the symmetry of a given
>         phonon mode     in quantum espresso
> To: PWSCF Forum <[email protected]>
> Message-ID: <1728518.gkaUiGcZ5e@paulaxps>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> On Friday, 12 May 2017 23:44:33 CEST Mihiri Hewa bosthanthirige wrote:
>> Hi,
>> I am graduate student at Clemson university, currently working with Quantum
>> Espresso. I would like to know how to determine the symmetry of a given
>> phonon mode in quantum espresso.
> 
> Hello,
> it is printed in the output of phonon at the end of the calculation, i.e.:
> ...
>     End of self-consistent calculation
> 
> 
> --
> Dr. Lorenzo Paulatto
> IdR @ IMPMC -- CNRS & Universit? Paris 6
> +33 (0)1 44 275 084 / skype: paulatz
> http://www.impmc.upmc.fr/~paulatto/
> 23-24/4?16 Bo?te courrier 115,
> 4 place Jussieu 75252 Paris C?dex 05
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> ------------------------------
> 
> Message: 2
> Date: Sat, 13 May 2017 16:09:02 +0200
> From: Davide Ceresoli <[email protected]>
> Subject: Re: [Pw_forum] Gipaw - Magnetic susceptibility
> To: PWSCF Forum <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=windows-1252; format=flowed
> 
> Dear Alan,
>      I think that there is no problem in doing a G=0 response
> with a shifted mesh. The response is at G=0, hence it couples
> wfcs at the same k. The susceptibility depends a lot on k-points
> sampling and if your system has a vanishing band gap, convergence
> can be a nightmare.
> By default the macroscopic shape is diagonal:
>    nmr_macroscopic_shape(:,:) = 0.d0
>    nmr_macroscopic_shape(1,1) = 2.d0 / 3.d0
>    nmr_macroscopic_shape(2,2) = 2.d0 / 3.d0
>    nmr_macroscopic_shape(3,3) = 2.d0 / 3.d0
> You can change the component (demagnetizing field) in the input file.
> 
> Good luck for your calculations!
> 
> Best,
>      Davide
> 
> 
> 
> On 05/12/2017 07:47 PM, Ambrozio wrote:
>> Dear QE users and Developers,
>>
>> I'm working with NMR calculations in Gipaw. Recently I did some shielding
>> calculations and I have some questions regarding the magnetic susceptibility.
>> The article from developers Mauri et al (*PRL 77, 26, 1996*) explain that the
>> shielding of a bulk of a periodic system is also periodic (i.e. has the same
>> periodicity of *G*, the reciprocal lattice vectors), and it is proportional 
>> to
>> the magnetic susceptibility matrix. In the paper Mauri did a short discussion
>> about the macroscopic susceptibility, which is calculated at *G=0*. Follow my
>> questions:
>>
>> i) Assuming that the macroscopic susceptibility is calculating at gamma point
>> (*G=0*) and depends of the sample's shape, Does make sense to do a NMR
>> calculation with automatic kpoints (monkhorst pack grid)  that does not 
>> include
>> the gamma point? It is mandatory to including the gamma point when the shape
>> correction is .true.?
>>
>> ii) Does the susceptibility depends of the supercell size? I found very
>> different susceptibilities for the same material (AB graphite) changing the
>> supercell size.
>>
>> iii) Why the susceptibility  matrix is not diagonal when the shape 
>> correction is
>> .true.? Assuming the Mauri paper I think it doens't make sense. Help me to
>> understand...
>>
>>
>> I appreciate any help,
>>
>> Thanks in advance,
>>
>>
>> Alan.
>>
>>
>>
>> --
>>
>> Alan J. Romanel Ambrozio
>> Bacharel em F?sica
>> Mestre em Eng. de Materiais
>> Doutorando em F?sica - PPGFis
>>
>>
>>
> 
> --
> +--------------------------------------------------------------+
>    Davide Ceresoli
>    CNR Institute of Molecular Science and Technology (CNR-ISTM)
>    c/o University of Milan, via Golgi 19, 20133 Milan, Italy
>    Email: [email protected]
>    Phone: +39-02-50314276, +39-347-1001570 (mobile)
>    Skype: dceresoli
>    Website: http://sites.google.com/site/dceresoli/
> +--------------------------------------------------------------+
> 
> 
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> End of Pw_forum Digest, Vol 118, Issue 12
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-- 
Pietro Bonfa'
Dipartimento di Fisica e Scienze della Terra "Macedonio Melloni"
Viale delle Scienze 7A
43124 Parma - Italy
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