Thank you Nick for the reply. 1. So long story short, 1 1 100 is considered a converged K pt set for the electrode but not necessary for the entire system.
When you said: 2) start with this k-point sampling for your transiesta calculation and check if the electronic structure changes if you further increase k-points Does that mean I can just start with TranSIESTA at 1 1 100, then look at its total energy or PDOS. Then try 3 1 100, 5 1 100 and so on and do a convergence test WITHOUT DOING THE SAME FOR THE ELECTRODES? Is that correct? OR should I start from the electrode calculations every single time? I am asking that because I was surprised from 1): 1) converge your electrode transverse k-points, using 100 k-points along the semi-infinite direction is fine The reason for all what I have asked is because I assumed number 3 is enough to converge my k points but it does not seem to be the case. Looking forward to your thoughts Nick. EL-abed El-abed Haidar | Doctor of Philosophy (Science) Condensed Matter Theory (CMT) Group| School of Physics THE UNIVERSITY OF SYDNEY | NSW | 2006 From: Nick Papior<mailto:nickpap...@gmail.com> Sent: Tuesday, 2 March 2021 8:06 AM To: siesta-l<mailto:siesta-l@uam.es> Subject: Re: [SIESTA-L] About TbTrans and K points Like any other DFT calculation you have to converge the physical properties with k-points. With TranSiesta + TBtrans this is no different. A basic scheme could be this: 1) converge your electrode transverse k-points, using 100 k-points along the semi-infinite direction is fine 2) start with this k-point sampling for your transiesta calculation and check if the electronic structure changes if you further increase k-points 3) Once you have found a suitable k-point sampling for the electronic structure you need to converge the current + DOS in tbtrans, this usually takes many more k-points than transiesta. But you shouldn't redo the transiesta calculations with these k-points samplings! Den lør. 27. feb. 2021 kl. 22.01 skrev El-abed Haidar <ehai2...@uni.sydney.edu.au<mailto:ehai2...@uni.sydney.edu.au>>: Good evening everyone, Sorry if this question has been answered before but I was wondering: When we start with a transport study we choose 1 1 100 for electrode and then scattering calculations to save time. The reason is to make sure we have a large k point set with 100 in the transport direction and as a result I get myself some I-V curve. My question is if I want to increase the number of K points can I start with the TbTrans and increase the k points using TBT.k[ a 1 100] with a >1 ? Or am I suppose to start from the beginning with increasing K points ? Why and thank you! El-abed El-abed Haidar | Doctor of Philosophy (Science) Condensed Matter Theory (CMT) Group| School of Physics THE UNIVERSITY OF SYDNEY | NSW | 2006 -- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/<https://protect-au.mimecast.com/s/jFLZCNLJyQUg7A6DFmrwJs?domain=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/)
