[WARNING] [X] Metallic system

[Daniele Varsano]

Dear Samira,

I cannot help on the modeling of your system, for this you should discuss with your supervisor.
What can happen when you add vacancies in your system is that the energy defect state it is not in the gap but fall in conduction band and this gives you a metallic system. This happens because GGA approximation is not enough to localize the state and DFT+U is
used to localize it. But again, this is not related with Yambo and you should discuss with your supervisors and your colleagues.

Best,
Daniele

[Sam-2025]

Dr. Daniele Varsano,

Thank you so much. I used the DFT+U, but this time I got the warning that yambo doesn't consider DFT+U.
Should I compile the yambo with specific way?

[Daniele Varsano]

Dear Samira,

The possibility to perform GW calculations on top of DFT+U is under development and at moment it cannot be used.
In line of principle, it would be possible to perform BSE only. Let me know if you are interested in the BSE without performing GW and I'll tell you how to modify the source to avoid the error message.

Best,
Daniele

[Sam-2025]

Dear Dr. Daniele Varsano,

Yes please, could you please guide me how should I check it. For now, I can go with a scissor for BSE.

I found the following on forum, but the p2y file is not readable, did I understand it correctly, If not (Because I am not the one who installed the YAMBO ) , could you please guide me. Thank you so much. I really appreciate it.


1) in interface/p2y/mod_p2y.F
change line 909
Code: Select all
if(pw_lda_plus_u) call error(' LDA+U. Hubbard correction is not considered in yambo.')
in
Code: Select all
if(pw_lda_plus_u) call warning(' LDA+U. Hubbard correction is not considered in yambo.')
2) You cannot get rid at the moment, so you cannot do GW calculations on top of DFT+U but only BSE directly (eventually using some

[Daniele Varsano]

Dear Samira,

as you reported, it is needed to change that lines in mod_p2y.F
essentially, substitute "error" with "warning". Note it appears twice in the same file (this depends on the QE format) and you can modify both the calls.
After the substitution is needed to recompile p2y (make interfaces).

Best,

Daniele