number of electrodes?

[azamat]

In  two probe Systems the number of electrodes on both sides is how? Should the same number of electrodes on each side be? (For example, both the number two gold atoms?) If a state system in the center of an atom to have and in another case two atoms have (Even and odd numbers of atoms in central region), how is the number of electrodes on each side?
Thanks

[youngjfly]

you mean the number of screening layers in the central region.
actually,it depends on the results of SCF.you don't have to add more atoms until the result changes little.otherwise,it will take more calculation time.
besides,the number of atoms don't have to be the same if only the structure obeys  the periodicity .
i am a rookie , this is only my  comprehension

[zh]

Usually, the number of atomic layers in the left electrode is not required to be same as the one of atomic layers in the right electrode. When the two electrodes have the same materials, for example, both of them consists of gold, it is more natural to build the two electrodes with same number of atomic layers.