Problem in Band Structure Plotting

[shahid-sattar]

While plotting a band structure along the high-symmetry k-path K->Gamma-> Kp, I noticed that the k-path distances are not symmetrical around Gamma, which should not happen due to a hexagonal brillouin zone.
Can you please suggest any solution for this issue?

[ahromero]

Shahid Could you please post more info about your problem. Which code? How did you find your K-PATH? Etc… without that, it is hard to track the problem… Thanks

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______________________::::__________________________________________ Prof. Aldo Humberto Romero Fellow American Physical Society Assistant Editor EPJB Member of the Editor Board of “Materials” Physics and Astronomy Department West Virginia University Phone: (304) 2936317 email: alromero@mail.wvu.edu From: Shahid Sattar <notifications@github.com> Date: Thursday, January 28, 2021 at 6:26 AM To: romerogroup/pyprocar <pyprocar@noreply.github.com> Cc: Subscribed <subscribed@noreply.github.com> Subject: [romerogroup/pyprocar] Problem in Band Structure Plotting (#44) While plotting a band structure along the high-symmetry k-path K->Gamma-> Kp, I noticed that the k-path distances are not symmetrical around Gamma, which should not happen due to a hexagonal brillouin zone. Can you please suggest any solution for this issue? [Figure_6]<https://user-images.githubusercontent.com/61748682/106132217-f67d5e80-6163-11eb-8a10-7bb7561611cc.jpeg> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#44>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AB24DTM344FHVCOIAWJIUY3S4FCV3ANCNFSM4WW4PNEA>.

[shahid-sattar]

I used VASP for band structure calculation of a 2D hexagonal system, automatically generating the K-path:

K-Points
35
line
reciprocal
        0.33333333333  0.33333333333  0.00000000000    ! K
        0.00000000000  0.00000000000  0.00000000000    ! \Gamma

        0.00000000000  0.00000000000  0.00000000000    ! \Gamma
       -0.33333333333  0.66666666667  0.00000000000    ! K'

       -0.33333333333  0.66666666667  0.00000000000    ! K'
        0.00000000000  0.50000000000  0.00000000000    ! M

        0.00000000000  0.50000000000  0.00000000000    ! M
        0.00000000000  0.00000000000  0.00000000000    ! \Gamma

[uthpalaherath]

Hello Shahid, Are K and K’ symmetrically equivalent? The distance between Gamma-K and Gamma-K’ are different based on your K-path. Please correct me if I'm wrong Best, Uthpala

On Thu, Jan 28, 2021 at 12:38 PM Shahid Sattar ***@***.***> wrote: I used VASP for band structure calculation of a 2D hexagonal system, automatically generating the K-path: K-Points 35 line reciprocal 0.33333333333 0.33333333333 0.00000000000 ! K 0.00000000000 0.00000000000 0.00000000000 ! \Gamma 0.00000000000 0.00000000000 0.00000000000 ! \Gamma -0.33333333333 0.66666666667 0.00000000000 ! K' -0.33333333333 0.66666666667 0.00000000000 ! K' 0.00000000000 0.50000000000 0.00000000000 ! M 0.00000000000 0.50000000000 0.00000000000 ! M 0.00000000000 0.00000000000 0.00000000000 ! \Gamma — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#44 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AG3ZXMLUPFKTI3UFK6CP7Z3S4GOI3ANCNFSM4WW4PNEA> .

-- Uthpala Herath PhD Candidate Department of Physics and Astronomy West Virginia University Morgantown, WV 26505 Tel. (304) 216-2535 Email: ukh0001@mix.wvu.edu <ukherathmudiyanselag@mix.wvu.edu> Website: https://uthpalaherath.github.io/

[shahid-sattar]

Hi Uthpala,
Yes, as it is a 2D system, K and K' are symmetrically equivalent.
In fact I plotted the same band structure using p4v and found K/K' at symmetrical distance to Gamma.
I also tried calculating the band structure separating K-G and G-K' and used combined PROCAR but it gives the same.

[ahromero]

Ja!.. right Your K’

-0.33333333333 0.66666666667 0.00000000000 ! K'

Is equivalent to 0.666666667 0.3333337 0.000000 Which is not equal to K 0.33333333333 0.33333333333 0.00000000000

______________________::::__________________________________________ Prof. Aldo Humberto Romero Fellow American Physical Society Assistant Editor EPJB Member of the Editor Board of “Materials” Physics and Astronomy Department West Virginia University Phone: (304) 2936317 email: alromero@mail.wvu.edu From: Uthpala Herath <notifications@github.com> Date: Thursday, January 28, 2021 at 12:46 PM To: romerogroup/pyprocar <pyprocar@noreply.github.com> Cc: Aldo Romero <Aldo.Romero@mail.wvu.edu>, Comment <comment@noreply.github.com> Subject: Re: [romerogroup/pyprocar] Problem in Band Structure Plotting (#44) Hello Shahid, Are K and K’ symmetrically equivalent? The distance between Gamma-K and Gamma-K’ are different based on your K-path. Please correct me if I'm wrong Best, Uthpala

On Thu, Jan 28, 2021 at 12:38 PM Shahid Sattar ***@***.***> wrote: I used VASP for band structure calculation of a 2D hexagonal system, automatically generating the K-path: K-Points 35 line reciprocal

! K

0.00000000000 0.00000000000 0.00000000000 ! \Gamma 0.00000000000 0.00000000000 0.00000000000 ! \Gamma -0.33333333333 0.66666666667 0.00000000000 ! K' -0.33333333333 0.66666666667 0.00000000000 ! K' 0.00000000000 0.50000000000 0.00000000000 ! M 0.00000000000 0.50000000000 0.00000000000 ! M 0.00000000000 0.00000000000 0.00000000000 ! \Gamma — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#44 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AG3ZXMLUPFKTI3UFK6CP7Z3S4GOI3ANCNFSM4WW4PNEA> .

-- Uthpala Herath PhD Candidate Department of Physics and Astronomy West Virginia University Morgantown, WV 26505 Tel. (304) 216-2535 Email: ukh0001@mix.wvu.edu <ukherathmudiyanselag@mix.wvu.edu> Website: https://uthpalaherath.github.io/ — You are receiving this because you commented. Reply to this email directly, view it on GitHub<#44 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AB24DTKC6QTB6IDVWYDTZWTS4GPHFANCNFSM4WW4PNEA>.

[ahromero]

Shahid They could be symmetrically the same but we are not taking that into account, the only symmetries we apply are based on the values you give from K and K’ and they are not the same point… of course, you can always use rotation to prove that K and K’ but we do not apply any point symmetry operations… we could do it in the future but right now we are reengineering the whole package to allow more properties to be implemented… this will have to wait…

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______________________::::__________________________________________ Prof. Aldo Humberto Romero Fellow American Physical Society Assistant Editor EPJB Member of the Editor Board of “Materials” Physics and Astronomy Department West Virginia University Phone: (304) 2936317 email: alromero@mail.wvu.edu From: Shahid Sattar <notifications@github.com> Date: Thursday, January 28, 2021 at 12:48 PM To: romerogroup/pyprocar <pyprocar@noreply.github.com> Cc: Aldo Romero <Aldo.Romero@mail.wvu.edu>, Comment <comment@noreply.github.com> Subject: Re: [romerogroup/pyprocar] Problem in Band Structure Plotting (#44) Hi Uthpala, Yes, as it is a 2D system, K and K' are symmetrically equivalent. In fact I plotted the same band structure using p4v and found K/K' at symmetrical distance to Gamma. I also tried calculating the band structure separating K-G and G-K' and used combined PROCAR but it gives the same. — You are receiving this because you commented. Reply to this email directly, view it on GitHub<#44 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AB24DTPGHMN6BJVPPQHKEU3S4GPOJANCNFSM4WW4PNEA>.

[shahid-sattar]

Thanks a lot for your prompt response.
Update:
I tried the option of kdirect=False and it worked. Now the distances are equal from K-G and G-K'.

pyprocar.bandsplot('PROCAR',outcar='OUTCAR',elimit=[-2.5,2.5],kpointsfile='KPOINTS',cmap='jet',kdirect=False,mode='parametric',spin=1)

[uthpalaherath]

I see. That option converts the coordinate system from reduced to Cartesian. I guess with the coordinate transformation they would become the same point. I’m glad it worked out for you. Best, Uthpala

On Thu, Jan 28, 2021 at 12:54 PM Shahid Sattar ***@***.***> wrote: Thanks a lot for your prompt response. Update: I tried the option of kdirect=False and it worked. Now the distances are equal from K-G and G-K'. pyprocar.bandsplot('PROCAR',outcar='OUTCAR',elimit=[-2.5,2.5],kpointsfile='KPOINTS',cmap='jet',kdirect=False,mode='parametric',spin=1) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#44 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AG3ZXMINXQ6NFLUVKU6MKLDS4GQFJANCNFSM4WW4PNEA> .

-- Uthpala Herath PhD Candidate Department of Physics and Astronomy West Virginia University Morgantown, WV 26505 Tel. (304) 216-2535 Email: ukh0001@mix.wvu.edu <ukherathmudiyanselag@mix.wvu.edu> Website: https://uthpalaherath.github.io/