Re: [Pw_forum] Shifted_Vs_Unshifted

[Ari P Seitsonen]

Dear Amir-who-is-missing-the-affiliation-in-the-post,

  A small clarification to Lorenzo's-who-did-not-even-sign-the-post 
answer, in principle both would mathematically give the same accuracy, but 
due to the pecularities in the density of states in particular regions of 
the Brillouin zone one or the other could lead to faster convergence, like 
Lorenzo wrote. Traditionally one tries to avoid the Gamma point, as one 
thinks that it is an "extreme point" in the band structure (it is a local 
minimum or maximum of each band, as their derivatives with respect to any 
direction in k space is zero). Earlier this was of more importance, when 
one could afford few k points and/or the systems were small, nowadays 
choosing one or the other is no longer that important, as the increased 
computing power makes the inclusion of more k points or larger cell 
easier.


  And just to bore all the reader of the Forum, I remind you that in 
hexagonal cell it is better to keep a Gamma-centred Monkhorst-Pack grid, 
as otherwise the k point grid will get symmetrised (if this would not be 
done, the grid would have a lower symmetry than the hexagonal cell 
itself).


  And for historical note, the original Monkhorst-Pack grid corresponds to 
the case "1 1 1", the shift was actually introduced later (when they were 
indeed notified about the problem in the hexagonal case; references are a 
Comment and Reply to Comment to the original Article of Monkhorst and 
Pack). So in this sense the convention in QE of "shifted" and "unshifted" 
k point sets are opposite to the ones of the original literature. :)


Greetings from Paris,

   apsi

-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
  Ari Paavo Seitsonen / ari.p.seitso...@iki.fi / http://www.iki.fi/~apsi/
Ecole Normale Supérieure (ENS), Département de Chimie, Paris
Mobile (F) : +33 789 37 24 25(CH) : +41 79 71 90 935


On Tue, 8 Mar 2016, Lorenzo Paulatto wrote:



If you use 1's the grid will be shifted by half its step, this makes the 
integrals of the grid convergence faster in some cases.

On 8 Mar 2016 8:51 p.m., "Mofrad, Amir Mehdi (MU-Student)" 
 wrote:

  Dear all QE users and developers,


  I have a question about the K_POINTS card in the input file. What is the 
difference between using shifted (1 1 1) and unshifted (0 0 0)?


  Best,



  Amir M. Mofrad


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Re: [Pw_forum] Shifted_Vs_Unshifted

[Lorenzo Paulatto]

If you use 1's the grid will be shifted by half its step, this makes the
integrals of the grid convergence faster in some cases.
On 8 Mar 2016 8:51 p.m., "Mofrad, Amir Mehdi (MU-Student)" <
am...@mail.missouri.edu> wrote:

> Dear all QE users and developers,
>
>
> I have a question about the K_POINTS card in the input file. What is the
> difference between using shifted (1 1 1) and unshifted (0 0 0)?
>
>
> Best,
>
>
>
> Amir M. Mofrad
>
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Re: [Pw_forum] Restart pw.x in a different machine

[Joshua Davis]

Dear Joaquim,

you may want to look up the "wfcollect" option under 

http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#__top__

Joshua Davis
Michigan State University

On Tue, Mar 8, 2016 at 2:11 PM Malicious Scientist <
scientist.malici...@gmail.com> wrote:

> Dear Nicola,
>
> Sorry, my mistake.
>
> ---
> Name: Joaquim José Xavier
> Institution: Faculdade de Educação, Ciências, e Letras do Sertão Central -
> Quixadá - Ceará - Brasil
> http://www.uece.br/feclesc/
> ---
>
> On Tue, Mar 8, 2016 at 3:42 PM, Nicola Marzari 
> wrote:
>
>>
>> Dear Malicious,
>>
>> PLEASE see the posting guidelines:
>> http://www.quantum-espresso.org/forum/#1.0
>>
>> *Sign your post with your name and affiliation.*
>>
>> nicola
>>
>>
>>
>> On 08/03/2016 19:37, Malicious Scientist wrote:
>> > Hello Community,
>> >
>> > I would like to know if it is possible top stop a pw.x run, copy to
>> > files to a different machine, and then restart the computation.
>> >
>> > For example, to stop the execution, I would create a $prefix.EXIT file
>> > on the working directory (just like described at
>> >
>> http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html
>> ).
>> >
>> > After that, I would copy the entire working directory, including the
>> > scratch dir, to a remote server with the same version of QE installed.
>> > Then I would restart the computation setting the 'restart_mode' flag to
>> > 'restart' at the CONTROL namelist.
>> >
>> > Is this supposed to work? If so, may I restart the computation with a
>> > different number of CPUs?
>> >
>> > Thank you for your attention.
>> >
>> >
>> > ___
>> > Pw_forum mailing list
>> > Pw_forum@pwscf.org
>> > http://pwscf.org/mailman/listinfo/pw_forum
>> >
>>
>> --
>> --
>> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
>> Director, National Centre for Competence in Research NCCR MARVEL, EPFL
>> http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project
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>>
>
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[Pw_forum] Shifted_Vs_Unshifted

[Mofrad, Amir Mehdi (MU-Student)]

Dear all QE users and developers,


I have a question about the K_POINTS card in the input file. What is the 
difference between using shifted (1 1 1) and unshifted (0 0 0)?


Best,



Amir M. Mofrad
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Re: [Pw_forum] Restart pw.x in a different machine

[Malicious Scientist]

Dear Nicola,

Sorry, my mistake.

---
Name: Joaquim José Xavier
Institution: Faculdade de Educação, Ciências, e Letras do Sertão Central -
Quixadá - Ceará - Brasil
http://www.uece.br/feclesc/
---

On Tue, Mar 8, 2016 at 3:42 PM, Nicola Marzari 
wrote:

>
> Dear Malicious,
>
> PLEASE see the posting guidelines:
> http://www.quantum-espresso.org/forum/#1.0
>
> *Sign your post with your name and affiliation.*
>
> nicola
>
>
>
> On 08/03/2016 19:37, Malicious Scientist wrote:
> > Hello Community,
> >
> > I would like to know if it is possible top stop a pw.x run, copy to
> > files to a different machine, and then restart the computation.
> >
> > For example, to stop the execution, I would create a $prefix.EXIT file
> > on the working directory (just like described at
> >
> http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html
> ).
> >
> > After that, I would copy the entire working directory, including the
> > scratch dir, to a remote server with the same version of QE installed.
> > Then I would restart the computation setting the 'restart_mode' flag to
> > 'restart' at the CONTROL namelist.
> >
> > Is this supposed to work? If so, may I restart the computation with a
> > different number of CPUs?
> >
> > Thank you for your attention.
> >
> >
> > ___
> > Pw_forum mailing list
> > Pw_forum@pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
> >
>
> --
> --
> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
> Director, National Centre for Competence in Research NCCR MARVEL, EPFL
> http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project
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Re: [Pw_forum] Restart pw.x in a different machine

[Nicola Marzari]

Dear Malicious,

PLEASE see the posting guidelines:
http://www.quantum-espresso.org/forum/#1.0

*Sign your post with your name and affiliation.*

nicola



On 08/03/2016 19:37, Malicious Scientist wrote:
> Hello Community,
>
> I would like to know if it is possible top stop a pw.x run, copy to
> files to a different machine, and then restart the computation.
>
> For example, to stop the execution, I would create a $prefix.EXIT file
> on the working directory (just like described at
> http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html).
>
> After that, I would copy the entire working directory, including the
> scratch dir, to a remote server with the same version of QE installed.
> Then I would restart the computation setting the 'restart_mode' flag to
> 'restart' at the CONTROL namelist.
>
> Is this supposed to work? If so, may I restart the computation with a
> different number of CPUs?
>
> Thank you for your attention.
>
>
> ___
> Pw_forum mailing list
> Pw_forum@pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>

-- 
--
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
Director, National Centre for Competence in Research NCCR MARVEL, EPFL
http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project
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[Pw_forum] Restart pw.x in a different machine

[Malicious Scientist]

Hello Community,

I would like to know if it is possible top stop a pw.x run, copy to files
to a different machine, and then restart the computation.

For example, to stop the execution, I would create a $prefix.EXIT file on
the working directory (just like described at
http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html
).

After that, I would copy the entire working directory, including the
scratch dir, to a remote server with the same version of QE installed. Then
I would restart the computation setting the 'restart_mode' flag to
'restart' at the CONTROL namelist.

Is this supposed to work? If so, may I restart the computation with a
different number of CPUs?

Thank you for your attention.
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Re: [Pw_forum] nmr chemical shift

[Carlo Nervi]

The best approach is to compute the NMR parameters of a standard substance
thet Solid State NMR people are using. That depend on the nuclei you are
investigating. For example hexametilbenzene.
Once you have the absolute shielding of the reference it is easy to report
all the other chemical shifts.
HTH,
Carlo

2016-03-08 12:07 GMT+01:00 Tiana Davide :

> Dear all,
>
>
> I am calculating some nmr spectra using Gipaw.
>
> Since I've never done for solid state (namely periodic bulk) I was
> wondering how can I calculate the chemical shift?
>
>  Is the reference still TMS?
>
> if yes do I need to somehow find the TMS crystal structure or can I simply
> run a single molecule TMS?
>
> if not how can I do it?
>
>
> Cheers
>
> Davide
>
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-- 


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Fax: +39 0116707855  -  Dipartimento di Chimica, via
P. Giuria 7, 10125 Torino, Italy.http://lem.ch.unito.it/
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[Pw_forum] ENVIRON vs COSMO solvation models

[Giuseppe Mattioli]

Dear All
I was studying the documentation of the ENVIRON 0.2 plugin and it seems that 
water only is coded as solvent for isolated molecules. I was wondering 
whether there is somewhere a subset of variables (which I was not able to 
found...) that setup alternative dielectric media as in the case of the 
COSMO model (cited in the ENVIRON documentation), which basically requires the 
solvent dielectric constant (ground state DFT) or dielectric 
constant+refractive index (TDDFT) only.
Thank you in advance
Giuseppe


- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et 
imprescriptibles de l'homme. Ces droits sont la liberté,
la propriété, la sûreté et la résistance à l'oppression.


   Giuseppe Mattioli
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
   v. Salaria Km 29,300 - C.P. 10
   I 00015 - Monterotondo Stazione (RM), Italy
   Tel + 39 06 90672836 - Fax +39 06 90672316
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   ResearcherID: F-6308-2012

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Re: [Pw_forum] Orbital weight for bandstructure calculation in quantum espresso

[Guido Fratesi]

Dear Liming,

yes you can. See PP/examples/examples02 where this is done for bulk Ni.
Just have a band structure calculation than a projwfc.x run with 
kresolveddos=.true.

Depending on the further graphical processing, you may want to plot the 
PDOS_nlm(k,E) as a color map, or extract the weight of the states you 
want to plot from the output of projwfc.x, or check the 
prefix.save/atomic_proj.xml file.

Hope this helps
Guido

On 08/03/2016 07:49, L.M J wrote:
> Dear all
>
> I saw few papers include the orbital weight in their calculated band
> structure. For example, certain band energy is contributed by
> hybridization from "s & p" orbitals including how much percent of each
> orbital. Or see the example page(http://gvallver.perso.univ-pau.fr/?p=587)
>
> It there any way I can extract similar information by using quantum
> espresso?
>
> Thanks for advance.
>
> Kind regards,
> Liming

-- 
Guido Fratesi

Dipartimento di Fisica
Universita` degli Studi di Milano
Via Celoria 16, 20133 Milano, Italy
web:   https://sites.google.com/site/guidofratesi/
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[Pw_forum] nmr chemical shift

[Tiana Davide]

Dear all,


I am calculating some nmr spectra using Gipaw.

Since I've never done for solid state (namely periodic bulk) I was wondering 
how can I calculate the chemical shift?

 Is the reference still TMS?

if yes do I need to somehow find the TMS crystal structure or can I simply run 
a single molecule TMS?

if not how can I do it?


Cheers

Davide
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