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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Dear Parham,<br>
<br>
I never studied quantum dots , so I cannot give a particular recommendation. But for the electric field in Berry phase formalism I can say that Gamma point only is not implemented in pw.x but it the default and only option in cp.x. In pw.x you can use one
kpoint but it has to be shifted (not gamma).<br>
<br>
>From my experience nberrycyc beyond 2 does not change any of the calculated properties I have tested. Even the default 1 is great.
<br>
<br>
It is up to you to decide how much field you need to apply. But there is a "computational" maximum that can be estimated by Egap/(L x k)
<br>
<br>
Egap: band gap<br>
L: supercell length<br>
K: kpoints along the length L<br>
<br>
<br>
Regards,<br>
Mostafa<br>
MIT<br>
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