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 <[email protected]> on behalf of Md. Jahid Hasan Sagor <[email protected]> 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
_______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
