appropriate LMAXMIX value for DFT+U calculations

To share experience including discussions about scientific questions.


Moderators: Global Moderator, Moderator

Post Reply
Message
Author
sophie_weber
Jr. Member
Jr. Member
Posts: 74
Joined: Wed Jul 07, 2021 11:17 am

appropriate LMAXMIX value for DFT+U calculations

#1 Post by sophie_weber » Fri Jul 28, 2023 2:56 pm

Hello,

I am investigating the magnetic properties of a slab with an insulating, antiferromagnetic transition-metal oxide, Cr2O3, interfaced with the heavy metal Pt. I am using LDA+U calculations within the Dudarev method using a U of 4 eV on the Cr d states. I have been setting LMAXMIX to 4 with the rational that I am using a U on just d states, and the VASP wiki advises to set LMAXMIX to 4 for systems with d states in DFT+U. However, I am struggling with convergence, and am wondering whether, even though I do not have a finite U value for the Pt, I should still set LMAXMIX to 6 because the Cr2O3-Pt heterostructure contains f electrons. The wording of the wiki is a bit unclear.

If someone can clarify this I would greatly appreciate it. Thank you in advance!

pedro_melo
Global Moderator
Global Moderator
Posts: 142
Joined: Thu Nov 03, 2022 1:03 pm

Re: appropriate LMAXMIX value for DFT+U calculations

#2 Post by pedro_melo » Wed Aug 02, 2023 9:16 am

Dear sophie_weber,

Would it be possible to have a look at your input files? This could help figuring out the issues with your calculation.

Kind regards,
Pedro Melo

sophie_weber
Jr. Member
Jr. Member
Posts: 74
Joined: Wed Jul 07, 2021 11:17 am

Re: appropriate LMAXMIX value for DFT+U calculations

#3 Post by sophie_weber » Thu Aug 24, 2023 7:22 am

Hello,

I am so sorry, I haven't checked the forum in a long time and didn't notice that you responded. Attached are example input files. There are convergence issues with and without implementing constrained magnetism.

Thank you in advance for your help,
Sophie
You do not have the required permissions to view the files attached to this post.

pedro_melo
Global Moderator
Global Moderator
Posts: 142
Joined: Thu Nov 03, 2022 1:03 pm

Re: appropriate LMAXMIX value for DFT+U calculations

#4 Post by pedro_melo » Mon Oct 16, 2023 12:31 pm

Dear Sophie,

My apologies, but I was not able to run your calculation. Do you happen to have a smaller system (with fewer atoms) where this problem shows up?

Kind regards,
Pedro

Post Reply