Good afternoon to whom it may concern, i really want to understand the in depth behind the kpoints in electron transport. I still feel after going through the siesta mail where I have asked about it before in https://www.mail-archive.com/siesta-l@uam.es/msg10916.html leading to https://www.mail-archive.com/siesta-l@uam.es/msg09386.html . However, the answers were not clear to be honest as i did not get the complete understanding out of this. I went back and read more about periodicity as suggested back here in https://www.mail-archive.com/siesta-l@uam.es/msg08489.html and as Cubot mentioned its not about periodicity that is usually defined in solid states. Any resources on k points for transport we can rely on or tutorials? Because I am more confused on the k points when defined for electron transport study. So im trying really and really would appreciate if there is a tutorial in the future for the latest siesta version to how we use k points BECAUSE
So far i understand that we will go through 3 steps 1-transiesta <electrod.fdf >electrode.out to calculate Hamiltonian and overlap matrix of electrodes 2-transiesta <scat.fdf >scattering.out to calculate density matrix of scattering region ] 3-tbtran <scat.fdf >.tbtrans.out to calculate current and transmission When papers define the k points to be 1 1 100 along electron transport i would assume we use in all siesta versions %block Monkhorst Pack and through out the 3 steps i assume i am using 1 1 100 in my entire calculation. I found out recently that once siesta run is done in step 2 and starts a transiesta run the k points change suddenly to 1 1 1. WHY???? It was mentioned https://answers.launchpad.net/siesta/+question/686603 but not enough explanation on the reason why. I am not sure why especially that i want my study to be infinite along x and y ( or lattice vector a and b) and finite in z ( or c vector). Now if I am suppose to add a block in each step above mentioned, what should I do to make sure all 3 steps have 1 1 100? IF NOT AGAIN WHY? I fully understand that i should do convergence tests for k points but i need to know also if that is always the case. Because i read that 1 1 100 is more than enough (based on literature and reading around the siesta mail) Would anyone be able to give their in sight thoughts as detailed as possible. Thank you 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/)
