[Wannier] Help: Optimising low lying bands for transport calculations

[Jesse Vaitkus]

Hello Wannier mailing list,

I am trying to use Wannier90 to replicate the low lying conduction bands of
a very entangled set of bands but I haven't been able to make much
progress. I'd like to use them for conduction properties and as such I'd
like to get them as correct about that point as possible.

As you can see below, the Fermi energy (black line) sits low in the
conduction band and as such I only care about bands in the local vicinity;
unfortunately the bands are very intertwined (there are several hundred
more above the visible axis).

DFT calculations were made using a 6x1x1 grid as the amount of padding in
the y,z directions should mean that Y and Z are being folded to zero; the
corresponding image goes from Gamma to X.

Is there any way I can treat them (the lowest two bands)
specifically/specially? If I'm not mistaken, when specifying a frozen
window it must encompass the entire band which as you can see leads to
something like 9 bands being in the frozen window not just the two I'm
interested in.

In any case, I have done this and the runs do not converge nor do the WF
centres make much sense. I would provide some of the output bands/centres
but they change greatly from case to case and often don't make any sense at
all.

If you think Wannier functions are not suited to this particular problem, I
am open to suggestions for possible alternatives.

[image: Inline images 1]

Cheers,
Jesse Vaitkus


-- 

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Mr. Jesse Vaitkus MAIP
BAppSc(Phys) Hons, BAppSc(Nano)

PhD candidate
Room 14.6.02

Chemical and Quantum Physics
School of Applied Sciences
RMIT University
Victoria 3001
Australia

jesse.vaitkus at rmit.edu.au
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