What's the difference of Small electrode and Big electrode ?

[fangyongxinxi]

Dear, I have one question:

We  test the I-V of  the center region, If we chose different electrodes, we will get different answers. For example lih2li modle,  we want to get the I-V of H2, so we can use the single Li atom as the electrode as the example said ,and we can  also use a big Au(3*3) electrode,  different electrodes will get different answers  cost different calculation time.
which one is better ?

Thank you.

[zh]

Dear, I have one question:
We  test the I-V of  the center region, If we chose different electrodes, we will get different answers.

Please state your question more clearly.  Of course, different electrodes such as the Li atomic chain and the bulk Au (i.e., it is described by a Au(3x3) semi-infinite slab) could give different transport properties (such as I-V curve and transmission spectrum) of H2, because the coupling between H2 and electrodes depends on the choice of electrodes.

For example lih2li modle,  we want to get the I-V of H2, so we can use the single Li atom as the electrode as the example said ,and we can  also use a big Au(3*3) electrode,  different electrodes will get different answers  cost different calculation time. which one is better ?

Neither is better. They are different.