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<div class="moz-cite-prefix">Dear Khalid,<br>
<br>
the initial projections can affect whether the wannierization
process finds the global minimum or just a local one. So you will
most likely get more compact functions if you use good projections
than if you use random projections. But you can give it a try, and
check what is the spread of the resulting Wannier functions. They
should be around just a few Angstroms (2-3 in my experience for
semiconductors, but can be more depending on the system). Also,
the Hamiltonian should be real when you are at the global minimum
(use hr_plot = T to check it). <br>
<br>
If you don't know anything about the character of the electronic
states in your system, then you should first project the Bloch
functions onto atomic orbitals centered on the ions, and check
which orbitals on which ions dominate in those bands that you want
to reproduce with Wannier functions. In VASP you need to set the
LORBIT = 10 tag to generate these orbital projections. It can give
you an idea about which orbitals and how many of them you need.<br>
<br>
Best,<br>
Aron Szabo<br>
<br>
<br>
On 03/26/2015 02:29 PM, Khalid Ibne Masood Khalid wrote:<br>
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<div>Dear Researchers,<br>
</div>
I am new to wannier90, and I apologize my physics is not
good enough. I have two questions:<br>
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1) When writing wannier input file (.win file) I have found
the projection block most painful. I am not sure where and
which orbitals to choose. (how many s and p should be
taken?) Does this initial approximated projection affect the
final transport result? If I take random projections, will
that be okay in transport problems ?<br>
<br>
</div>
2) I want to consider the effect of electrical field in
transport properties, for this I can take electric field in my
DFT calculations, but I was wondering whether I take the gamma
only option with electric field in my DFT calculation, will it
be allowed in wannierisation ?<br>
<br>
</div>
Thank you.<br>
</div>
<br>
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