Electrode Sizes fixed to mininal size

[AsifShah]

Dear Admin/Others,
When doing device from bulk, it chooses minimal electrode length as one atom. However, I want to keep 2 or 3 atoms as my electrode I tried changing +/-  as shown in attachment, also tried changing left & right values below (see attachment) & electrode extension length but it does not help change the electrode length & keeps it fixed as one atom. How to rectify it? I found that changing left & right values below had no effect on the electrode size. Kindly help.
Check the attachments below.

(The reason why I want to change it to 2 or 3 atoms is because in electrode validator it says large matrix elements error & asks to increase electrode size)

[Anders Blom]

Unless you have very special reasons, there should be no need to have more atoms in the electrode than needed to get the correct repetition. So if 1 atom does it, then leave it at that, it's all the software needs. The electrode extension, however, needs to be long enough to capture interaction distances etc, as you are probably thinking about and as our older tutorial material shows.

[AsifShah]

Thanks for your response.

But if I continue with 1 atom, the electrode validator shows not "NOT VALID Electrode & asks to increase number of atoms in Electrode" which unfortunately is not accessible to change as mentioned in my initial post?

Should I then ignore electrode validator message?

[AsifShah]

Dear Admin,
Can you kindly answer my question?
I am not able to resolve the issue of electrode length in electrode validator.

On the other hand, there seems no way to change length of electrode.

[Anders Blom]

The electrode validator is not valid anymore It is based on the old way of defining the electrodes. We should update it.

[AsifShah]

Ah Cool.
Thanks