Integrated DOS and molecular orbital in quantumatk

[Jahanzaib]

Hello
I have quick question: for bulk configuration - NonuniformGridConjugateGradientSolver and fast fourier solver are the best. I am having a system where I am using stanene nanoribbons and cluster on it (bulk configuration). How to choose Solver in this case?

1. Is there a way for COOP or OPDOS analysis in quantumatk?
2. How to calculate integrated DOS in quantumatk? or how to get an idea of molecular orbitals in bulk and device configurations?

Thank you

[Anders Blom]

I would still recommend FFT as the standard choice. You typically only need to modify the Poisson solver if you introduce special dielectric or metallic regions.

We don't have COOP analysis yet, it's on the idea list for the future though.

Integrated DOS can be computed easily just using the raw DOS data, although I guess the details depend a bit on how you define the integration, like is it only over energy, or you want it k-point resolved, etc? Note that you can also compute molecular eigenstates (for finite systems) and Bloch states (for periodic cases) with QuantumATK, this gives a direct 3D picture of the eigenstates.

[Jahanzaib]

Thank you so much for your detailed response.
I was interested for integrated DOS over energy - I successfully did that.

Need you expert view point for my system.

I have six width long nanoribbons long C direction as shown in figure. I just pick it randomly but I want to know what kind of analysis i should do to verify that this 6 width long nanoribbons is fine - similarly how I can do analysis that these 4 layers are also fine?

I haven't figure it out how long the nanoribbons should be? how many layers are needed?

Need your expert point of view on it.

Thank you