[QE-users] Phonon Dispersion of graphene

[PAULATTO Lorenzo]

Dear Jahid, you have to decide precisely what you want, than you may be able to simulate it in different ways. A width of 10nm is probably too large for a direct DFT calculation of phonons, in this case you can use the phonons for the unit cell and add the finite size as a perturbation with Green function methods. I know a paper where this is done, but there are probably others, and other methods. https://hal.archives-ouvertes.fr/hal-03011389


Hth


LP
________________________________
From: users <users-bounces at lists.quantum-espresso.org> on behalf of Md. Jahid Hasan Sagor <md.sagor at maine.edu>
Sent: Saturday, December 24, 2022 10:17:28 AM
To: Quantum ESPRESSO users Forum
Subject: [QE-users] Phonon Dispersion of graphene

Hi,

Please help if you can. I am trying to find out the dispersion relation of graphene. I know that to find out the relation I have to use pw.x, ph.x, q2r.x and matdyn.x. But the problem is, after applying all the packages, I might get a phonon dispersion relation of graphene which is infinitely long in x and y direction. However, in my model I am using a finite width of graphene around 10nm (24 unit cell in the vertical direction). Which command in QE can do this for me so that I can model a graphene which is infinitely long in x direction and 10 nm in y direction?

Best Regards
Md Jahid Hasan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20221224/9d168efa/attachment.html>