unphysical ELF for NdNiO2

Problems running VASP: crashes, internal errors, "wrong" results.

Moderators: Global Moderator, Moderator

Locked
Message
Author
foyevtsova
Newbie
Newbie
Posts: 3
Joined: Tue Nov 12, 2019 5:47 pm

unphysical ELF for NdNiO2

#1 Post by foyevtsova » Tue Apr 26, 2022 7:23 pm

Hello,

I want to calculate electron localization function for the novel infinite-layer nickelate NdNiO2. The result seems unphysical: the ELF is very low around Ni atoms where one expects it to be rather high because of the strongly localized 3d electrons. At the same time Quantum Espresso gives a physically reasonalbe picture, please, check the figure below.

Thank you,
Kateryna Foyevtsova
You do not have the required permissions to view the files attached to this post.

andreas.singraber
Global Moderator
Global Moderator
Posts: 231
Joined: Mon Apr 26, 2021 7:40 am

Re: unphysical ELF for NdNiO2

#2 Post by andreas.singraber » Fri Apr 29, 2022 2:36 pm

Hello Kateryna Foyevtsova!

Thank you for your report! My colleagues and I had a look at the problem and indeed we also found the behavior very unreasonable. All other VASP output strongly indicates localized 3d electrons around Ni but somehow the ELF calculation does not account for that. I will have a closer look and report back when I have an explanation.

All the best,

Andreas Singraber

marie-therese.huebsch
Full Member
Full Member
Posts: 175
Joined: Tue Jan 19, 2021 12:01 am

Re: unphysical ELF for NdNiO2

#3 Post by marie-therese.huebsch » Mon May 09, 2022 7:12 am

Dear Kateryna,

We looked into the problem and found that the current implementation depends strongly on the choice of the POTCAR. You can test this by using the GW POTCAR and will find contributions from Ni 3d electrons. We believe that with this pseudo-potential dependent ELF is not a good measure for electronic localisation and thus want to replace this (very old) implementation in a future release.

In the meantime, let me stress that the underlying Kohn-Sham orbitals are fine. You can see the Ni 3d character in the PROCAR file. I hope that the current issue does not cause too much inconvenience in your research project. Does it suffice for you to have the orbital character? Or do you perhaps want to look at partial charge densities or Wannier functions to gain inside about the localisation? There are many features that might help answer the scientific question you are posing.

Best regards,
Marie-Therese

foyevtsova
Newbie
Newbie
Posts: 3
Joined: Tue Nov 12, 2019 5:47 pm

Re: unphysical ELF for NdNiO2

#4 Post by foyevtsova » Tue May 10, 2022 10:37 pm

Dear Marie-Therese,

thank you very much for taking time to investigate this issue and to reply. As per your advice, I will resort to other ways of analysing electron localization in this material. I am looking forward to having a chance to appy the new VASP implementation of ELF.

Best regards,
Kateryna

marie-therese.huebsch
Full Member
Full Member
Posts: 175
Joined: Tue Jan 19, 2021 12:01 am

Re: unphysical ELF for NdNiO2

#5 Post by marie-therese.huebsch » Wed May 11, 2022 8:19 am

Thank you very much for understanding! We will continue to work on improving VASP.

Locked