Dear El-Abed,

Den ons. 22. aug. 2018 kl. 22.00 skrev El-abed Haidar <
[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

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