In other words, since quantum transport is studied in the z direction does that make the choice of the atoms only x and y dependent? If so why?
EL-ABed El-abed Haidar | Doctor of Philosophy (Science) Condensed Matter Theory (CMT) Group | School of Physics THE UNIVERSITY OF SYDNEY | NSW | 2006 ________________________________ From: El-abed Haidar Sent: Friday, 24 August 2018 6:08:29 AM To: [email protected] Subject: Re: [SIESTA-L] Transiesta questions Thank you nick for your time In my second question I was wondering how effective is the z coordinate onto the transport of the calculation. My supervisor tends to randomly choose the z component as long as the x and y coordinates are precisely chosen. Is there a reason for that? Thank you again El abed Sent from my iPhone On 24 Aug 2018, at 6:00 am, Nick Papior <[email protected]<mailto:[email protected]>> wrote: Dear El-Abed, Den ons. 22. aug. 2018 kl. 22.00 skrev El-abed Haidar <[email protected]<mailto:[email protected]>>: HELLO EVERYONE I wanted to ask you two Transiesta questions (of course your reply is at your time of convenience): 1) I have noticed in different transiesta calculations that many do the following: a- Left electrode calculation of lets say 50 gold atoms. b- Right electrode calculation of lets say 50 gold atoms. c- System calculation with more than 50 gold atoms in each electrode. The scattering region is just a molecule independent of gold. My question is Does that make any sense to you? I know that the physics behind it is simply that we are assuming by increasing the number of gold atoms in the WHOLE SYSTEM calculation that we are making the electrodes semi infinite. But I thought for calculation consistency the number of gold atoms in both electrodes should be the same through out the system calculation. Yes, this makes perfect sense. The additional layers in the scattering region ensures that the potential becomes smooth in the electrode layers. An explanation may be found in https://doi.org/10.1016/j.cpc.2016.09.022 which clarifies that the extra layers are used to screen off the scattering potential from the junction. 2) Does the z component of the atom in a transiesta make any difference in the calculation or not? If so why? I don't understand what you mean? Generally you want all atoms to be defined in the simulation box due to internal constraints. Thank you very much and looking forward to your reply. EL-Abed El-abed Haidar | Doctor of Philosophy (Science) Condensed Matter Theory (CMT) Group | School of Physics THE UNIVERSITY OF SYDNEY | NSW | 2006 -- Kind regards Nick
