Question of : interface builder -> surface cell -> Some matches are degenerate?

[Lim changmin]

Hello, I am trying to match some surface with interface builder.

There are a lot of surface cell that I could choose, however for some samples, the sentence "Some matches are degenerate" turns into red and show the degenerate match groups.

Could anyone please tell me what this means? and could it affect the calculation results?

Also how can I solve this degenerate issue?

[Anders Blom]

This is a rather new feature and I haven't yet encountered a case where it showed up. Would be helpful with some details about the configurations to reproduce and advise.

[Lim changmin]

Dear Anders Blom

I created the interface with silicon and Molybdenium with the orientation of Si=(110)/Mo=(001)
I attached the pictures that I saw.

The sentence  "Some matches are degenerate" turns into red.

There were no signs of errors after I created the structure, but I still have some concerns regarding this issue.

[Anders Blom]

I guess we do things slightly differently, but I don't see this message. I took Si and Mo crystals from the Database in the Builder, cleaved 110 and 001, and dropped on the Interface Builder, see below.
I use W-2024.09.

[Lim changmin]

Oh, I accidently forget to input more information.

I used the latest version of ATK and I optimized primitive cell of Si and Mo at 0.02eV/A tolerance.

Then I cleaved each with 110 and 001

[Anders Blom]

Can you attach the structures, then I can better try to assist. Note that I don't think there is a problem or bug here, you just need to figure out a way to pick the most relevant structure.

[Lim changmin]

Sorry for the late reply, I attached the structure information by .py files

[Anders Blom]

OK, these files produce some interesting results, and probably reveal a small bug which we can work on fixing.

But from a practical perspective, for you to carry on your work, from what I can tell it really doesn't matter which one you pick if two matches are degenerate, they are the same structure. I am not sure why we even bother to tell users about this...