Hi, Den tir. 16. jun. 2020 kl. 22.00 skrev Seyed Mohammad Tabatabaei < smt...@gmail.com>:
> Thank you so much for your answer. > > Do I need to use more buffer layers? > Maybe, first change to metallic MoS2, then see. > > I am currently using semiconducting MoS2 nanoribbons (1D system) with a > bandgap of about 0.5 eV. Would changing to metallic MoS2 nanoribbons > improve convergence? > Yes, using metallic electrodes would definitely help. > > Do you mean I should increase the cutt-off energy? > I didn't realize it was a nanoribbon. So no need for k-point convergence. But you should converge system parameters before doing NEGF calculations. This includes basis set optimization + mesh-cutoff etc. > > > > > > On Tue, Jun 16, 2020 at 12:36 AM Nick Papior <nickpap...@gmail.com> wrote: > >> Hi, >> >> 1. Great that you are using buffer atoms to get the *correct* behaviour >> of your electrodes >> 2. However, you are using MoS2 as electrodes, which is semiconducting. >> This is not a good idea since the NEGF formalism requires the electrodes >> are *bulk-like* and this cannot be enforced if the screening distance is >> very long. This is the case for semi-conducting electrodes. >> 3. Your other convergence parameters are very low, you really should >> first converge the basic MoS2 setup for k-points, mesh-cutoff etc. but in >> general, if you have semi-conducting electrodes, you shouldn't use NEGF >> unless you are being really careful. :) >> >> Den lør. 13. jun. 2020 kl. 22.00 skrev Seyed Mohammad Tabatabaei < >> smt...@gmail.com>: >> >>> Dear all, >>> >>> I am doing a TranSIESTA calculation for the following system. >>> >>> [image: image.png] >>> >>> However, I cannot converge the density matrix no matter how small my >>> mixing weight is. >>> >>> I would be grateful if you help me with it. My output file is also >>> attached. >>> >>> Best regards, >>> >>> >>> >>> -- >>> SIESTA is supported by the Spanish Research Agency (AEI) and by the >>> European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) >>> >> >> >> -- >> Kind regards Nick >> >> -- >> SIESTA is supported by the Spanish Research Agency (AEI) and by the >> European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) >> > > -- > SIESTA is supported by the Spanish Research Agency (AEI) and by the > European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) > -- Kind regards Nick
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
