[QE-users] Query regarding k path selection, mismatching of band gap

[Nicola Marzari]

On 13/10/2020 20:43, Poonam Kaushik wrote:
> Dear Expert,
> So the only option that I have is to include the complete path and do 
> the calculation again.
> Thank you so much for your suggestion.
> 

Mostly welcome, but you have three options - destiny can be generous 
sometimes.

The first option would be doing a more careful DOS: 
https://www.quantum-espresso.org/Doc/INPUT_DOS.html

			nicola

> 
> 
> Thanks and regards,
> Poonam Sharma
> 
> 
> 
> 
> -------------------------------------------------------------------------------------------------
> Poonam Sharma
> Research Scholar
> Department of Physics
> Indian Institute of Technology Bombay
> Mumbai - 400076
> India.
> 
> 
> 
> On Tue, Oct 13, 2020 at 11:53 PM Nicola Marzari <nicola.marzari at epfl.ch 
> <mailto:nicola.marzari at epfl.ch>> wrote:
> 
> 
> 
> 
>       From the most to the less likely, it could be that your DOS has some
>     broadening that masks the existence of a small gap, or that the gap
>     closes across the last two segments of the path that you are
>     missing, or
>     that you are very unlucky and the band gaps closes at points that do
>     not
>     lie on a high symmetry path.
> 
>                   nicola
> 
> 
>     On 13/10/2020 19:53, Poonam Kaushik wrote:
>      >
>      > Dear Experts,
>      >   I have one query regarding k path selection. After using Kpath
>     finder
>      > (https://www.materialscloud.org/work/tools/seekpath ), i got 
>     this type
>      > of  k path
>      > G-M-K-G-A-L-H-A|L-M|H-K for my structure. In the calculation, I
>     used, up
>      > to G-M-K-G-A-L-H-A. So, is this ok to select a path up to this?
>      > Basically in the band structure, I am getting some finite gap
>     while in
>      > dos I m getting a zero bandgap, after selecting the path up to
>      > G-M-K-G-A-L-H-A. I am not able to figure out why this is happening?
>      > Should it help to include the complete path? I am attaching here my
>      > input file, band structure, and dos. Please have a look.
>      >
>      >
>     https://drive.google.com/drive/folders/1UhUgod8KnvdovJfxMqbJMQwdtb3dE-yY
>      >
>      >   I'll be very thankful for any suggestions.
>      >
>      > Thanks and regards,
>      > Poonam Sharma
>      >
>      >
>      >
>      >
>     -------------------------------------------------------------------------------------------------
>      > Poonam Sharma
>      > Research Scholar
>      > Department of Physics
>      > Indian Institute of Technology Bombay
>      > Mumbai - 400076
>      > India.
>      >
>      >
>      > _______________________________________________
>      > Quantum ESPRESSO is supported by MaX (www.max-centre.eu
>     <http://www.max-centre.eu>)
>      > users mailing list users at lists.quantum-espresso.org
>     <mailto:users at lists.quantum-espresso.org>
>      > https://lists.quantum-espresso.org/mailman/listinfo/users
>      >
> 
> 
>     -- 
>     ----------------------------------------------------------------------
>     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
> 


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