[Pw_forum] method to create high-symmetry k-paths?

[Nicola Marzari]

Grazie Giovanni!

Let me also add that this was done in collaboration with the group of
Isao Tanaka to make sure that all definitions would be unique,
fully compliant with crystallographic standards (international
tables of crystallography) and always accounting for the space
group of the crystal - for many complex cases this is the first
time it is done. You can read more about their work here:
https://arxiv.org/abs/1602.06402

I was not involved, but I would warmly suggest that we try to
standardize around this.

			nicola



On 03/11/2016 16:29, Giovanni Pizzi wrote:
> Dear all,
>
> I would like to mention that I recently released a python tool (called
> SeeK-path) that allows you to get the list of k-points for any
> spacegroup, together with the suggested band path.
> You can find the code here: https://github.com/giovannipizzi/seekpath
> and there is also an online tool on the materials cloud website:
> http://materialscloud.org/tools/seekpath
>
> The website is useful for playing with it, but if you want to script it,
> you just need to install the python tool (pip install seekpath), pass
> the structure as input to the seekpath.get_path() function [you can
> parse the Quantum ESPRESSO input structure e.g. with ASE, or with the
> tools in AiiDA] and then write back the results in a file in the format
> you need.
>
> This should be straightforward to code, and in the future I might add
> routines to do this automatically for the most common file formats like
> matdyn (or feel free to fork the code and add the functionality, if you
> want!).
>
> Best,
> Giovanni
>
>
> On 11/03/2016 12:11 PM, Christoph Wolf wrote:
>> Dear Lorenzo!
>>
>> Thank you for your reply! Your work-flow is exactly like mine. I know this
>> works quite well but I find the copy-pasting-editing from the bands output a
>> bit tedious (yet I am too lazy to make a script...).
>>
>> Today I found however that the package "PlotPhon" contains a neat script
>> written by E.I. Isaev of Linkoping University, Sweden with a quite nice
>> generator for k-point paths for a few bravais lattices! It produces a file
>> ph.grid that contains exactly what I want.
>>
>> I will try and see how far it gets me!
>>
>> Best,
>> Chris
>>
>> Message: 6
>> Date: Thu, 03 Nov 2016 09:19:15 +0100
>> From: Lorenzo Paulatto <lorenzo.paulatto at impmc.upmc.fr>
>> Subject: Re: [Pw_forum] method to create high-symmetry k-paths?
>> To: PWSCF Forum <pw_forum at pwscf.org>
>> Message-ID: <1726820.3nKUJ2z1xf at naquite>
>> Content-Type: text/plain; charset="UTF-8"
>>
>> Hello Christoph,
>> what I usually do is I pick the high symmetry points from a paper, or the
>> Bilbao crystallographic server, or xcrysden and then I use the method
>> "tpiba_b" or "crystal_b" to generate the paths (or q_in_band_form=.true. in
>> matdyn.x, when doing phonons). See the K_POINTS section of INPUT_PW.html for
>> more details on the syntax, it is quite easy.
>>
>> hth
>>
>> On Thursday, November 3, 2016 1:01:05 AM CET Christoph Wolf(??????) wrote:
>>> Dear all!
>>>
>>> Sometimes I have to plot the phonon dispersion along a certain k-path
>>> (G->X->R?).
>>
>>> Usually I pick the k-path in xcrysden, then run a band structure
>> calculation
>>> with crystal_b, pick the k-path from the out-file and insert it into my
>>> matdyn in file. But that procedure, despite working well, is just
>>> cumbersome and I was wondering if there is a more direct way to generate
>>> the k-path (without coding my own, which I did for cubic but I am worried
>>> about other symmetries, weights, ?).
>>
>>> Obviously the routine is embedded in QE because it never failed to
>> generate
>>> a k-path during the band-structure calculation but I was not capable to
>>> access it directly!
>>
>>> Thank you for your help in advance!
>>>
>>> Yours,
>>> Chris
>>>
>>> Christoph Wolf
>>> Postech University, Pohang, South Korea
>>> Dep. Of Materials Science and Engineering
>>>
>>>
>>>
>>>
>> [http://home.postech.ac.kr/wp-content/themes/postech/images/mail_logo_postec
>>> h30.png]
>>   30POSTECH
>>
>>
>
>

-- 
----------------------------------------------------------------------
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