[QE-users] Query regarding k path selection, mismatching of band gap
Poonam Kaushik
poonamkaushik40 at gmail.com
Wed Oct 14 09:24:04 CEST 2020
Dear All,
I have one more concern about selecting the weight factor. I defined the
kpath (Γ—M—K—Γ—A—L—H—A|L—M|H—K)as:
K_POINTS {crystal_b}
8
0.0000000000 0.0000000000 0.0000000000 50 !G
0.5000000000 0.0000000000 0.0000000000 50 !M
0.3333333333 0.3333333333 0.0000000000 50 !k
0.0000000000 0.0000000000 0.0000000000 50 !G
0.0000000000 0.0000000000 0.5000000000 50 !A
0.5000000000 0.0000000000 0.5000000000 50 !L
0.3333333333 0.3333333333 0.5000000000 50 !H
0.0000000000 0.0000000000 0.5000000000 50 !A
0.5000000000 0.0000000000 0.5000000000 50 !L
0.5000000000 0.0000000000 0.0000000000 50 !M
0.3333333333 0.3333333333 0.5000000000 50 !H
0.3333333333 0.3333333333 0.0000000000 50 !K
Here I gave 50 points from one k points to another. Is this is ok, or
should I use as, from H to A 50 and the A to L 0 points, similarly for
M|H?
Γ— M — K — Γ — A— L— H— A|L— M| H— K
50- 50- 50- 50 - 50- 50- 50- 50|0- 50|0- 50
Thanks and regards,
Poonam Sharma
-------------------------------------------------------------------------------------------------
Poonam Sharma
Research Scholar
Department of Physics
Indian Institute of Technology Bombay
Mumbai - 400076
India.
On Wed, Oct 14, 2020 at 2:54 AM Poonam Kaushik <poonamkaushik40 at gmail.com>
wrote:
> Dear Vahid Askarpour,
> currently, I am trying by fixing occupation tetrahedra and fixed also.
> I'll update here if everything works fine.
> Thank you so much for your response and suggestion.
>
> Thanks and regards,
> Poonam Sharma
>
>
>
>
>
> -------------------------------------------------------------------------------------------------
> Poonam Sharma
> Research Scholar
> Department of Physics
> Indian Institute of Technology Bombay
> Mumbai - 400076
> India.
>
>
>
> On Wed, Oct 14, 2020 at 1:19 AM Poonam Kaushik <poonamkaushik40 at gmail.com>
> wrote:
>
>>
>> Dear Expert,
>> About the first option, I used to confuse to select the correct option
>> for the occupation, smearing type, and broadening part. In my input file, I
>> used an 'mv' smearing with a broadening of 0.02 Ry. So either I can reduce
>> it to 0.01 Ry or I can try any other occupation, like tetrahedra or
>> fixed. my system is an insulator with a small bandgap of 0.04 eV. Also in
>> the third option, I calculated the k path by using the CIF file, and
>> k-pathfinder. Please correct me if I am wrong.
>>
>> Thanks and regards,
>> Poonam Sharma
>>
>>
>>
>>
>>
>> -------------------------------------------------------------------------------------------------
>> Poonam Sharma
>> Research Scholar
>> Department of Physics
>> Indian Institute of Technology Bombay
>> Mumbai - 400076
>> India.
>>
>>
>>
>> On Wed, Oct 14, 2020 at 12:18 AM Nicola Marzari <nicola.marzari at epfl.ch>
>> wrote:
>>
>>> 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
>>>
>>
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