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Yambo with B2LYP
Posted: Tue Dec 13, 2022 1:48 pm
by Joe_Page_93
Hi,
I am using Quantum Espresso v7.0, and Yambo 5.0.4.
I am trying to calculate the band structure of a material using a hybrid function. I know that 'input_dft = "HSE",' doesn't work correctly with yambo, so i have been using 'input_dft = "b3lpv1r"'. After the SCF calculation has finished, and converged, i can use p2y to generate the SAVE folder and initialise it using the yambo command.
However, when i try to generate the input file for a Hartree Fock calculation (yamvo -x -F hf.in), the file generated is empty (apart fro the yambo header). If I input the parameters it manually, the output file isn't correct, given other HF calculations I have done.
Is there a step i am missing? As far as i am aware i am not missing any steps (as I cannot perform the nscf calc), But if anyone has any incite into this issue, please let me know.
Thanks you.
Re: Yambo with B2LYP
Posted: Tue Dec 13, 2022 2:58 pm
by Daniele Varsano
Dear Joe_Page_93,
first, let me ask you to sign your post with your name and affiliation, this is a rule of the forum! You can do once for all by filling your signature in the user profile.
If the p2y run successfully, most probably it is not a problem of the hybrid functional, but there should be something else preventing working correctly.
Can you post in attachment your setup file r_setup? You can attach to the post by renaming it, e.g. r_setup.txt
Best,
Daniele
Re: Yambo with B2LYP
Posted: Tue Dec 13, 2022 3:10 pm
by Joe_Page_93
Hi Daniele,
Okay, Its good that is not a hybrid problem as I have been trying to figure how to do an nscf calculation for a while now.
Sure. I have attached the r_setup file as suggested. Hope it helps.
Thank you again.
Joe
Re: Yambo with B2LYP
Posted: Wed Dec 14, 2022 9:08 am
by Daniele Varsano
Dear Joseph,
the problem is related to the fact your K grid is not seen as uniform by Yambo:
Code: Select all
[WARNING][RL indx] 2 equivalent points in the rlu grid found
[RL indx] X grid is not uniform. Gamma point only.
[WR./SAVE//ndb.kindx]-----------------------------------------------------------
Fragmentation : no
Polarization last K : 26
QP states : 1 26
X grid is uniform : no
Check your unit cell geometry and k point grid in the scf QE file.
If all seems OK, you can try to remove the ndb.* files in the SAVE directory and repeat the setup calculation, adding the following keyword in the input file:
and see if this solves the problem.
Best,
Daniele
Re: Yambo with B2LYP
Posted: Wed Dec 14, 2022 11:26 am
by Joe_Page_93
Hi Daniele,
So in my scf calculation i am using an automatic k-point grid, but i am also using ibrav = 0, as my unit call cannot be defined by the build in system. Could that be the reason behind the non-uniform K grid?
I re-ran the p2y command and check the SAVE folder, and none of the files where ndb.*. They where all ns.* (there was one ns.db1, but i assume thats not what you are on about). Is there something i have missed in the steps?
Thank you again,
Joe
Re: Yambo with B2LYP
Posted: Wed Dec 14, 2022 11:48 am
by Daniele Varsano
Dear Joe,
but i am also using ibrav = 0, as my unit call cannot be defined by the build in system. Could that be the reason behind the non-uniform K grid?
Yes, it is possible.
I re-ran the p2y command and check the SAVE folder, and none of the files where ndb.*
The ndb* file are created by Yambo, you should delete the ones created previously by the setup.
If you run p2y in a different directory, it is ok. it is important you start the setup from scratch.
Next, create a setup file using:
and activate the NoDiagSC keyword, which is commented by default, then run yambo:
Check in the report file if the grid is seen as uniform.
If it is not working, there is not much to do than find a way to define a unit cell using a bravais lattice.
Best,
Daniele