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<div class="moz-cite-prefix">On 06/21/2017 02:32 PM, Aguilera, Irene
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:6C025142-440B-4529-89E0-3967E78709C1@fz-juelich.de">
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font-family: Menlo; background-color: rgb(255, 255, 255);"
class="">
<span style="font-variant-ligatures: no-common-ligatures"
class="">...</span></div>
<div style="margin: 0px; font-size: 11px; line-height: normal;
font-family: Menlo; background-color: rgb(255, 255, 255);"
class="">
<span style="font-variant-ligatures: no-common-ligatures"
class=""></span><span style="font-variant-ligatures:
no-common-ligatures" class="">For those q points there is a
small splitting between the Kramers partners. So, I think I
understand why this happens and I understand how to improve it
and make the splitting negligible (increasing the k points in
the DFT calculation does it).</span></div>
</blockquote>
Dear Irene,<br>
<br>
increasing the DFT k-points grid helps for sure, but (if you are
using disentanglement) playing with the windows (especially the
frozen ones) may actually help a lot (and keeping a coarse k-points
grid will help you with GW). Typically in a good (converged
minimization, low spreads) wannierization that effect should be
negligible, even with rather coarse k-points grids.<br>
<br>
<blockquote type="cite"
cite="mid:6C025142-440B-4529-89E0-3967E78709C1@fz-juelich.de">
<div style="margin: 0px; font-size: 11px; line-height: normal;
font-family: Menlo; background-color: rgb(255, 255, 255);"
class=""><span style="font-variant-ligatures:
no-common-ligatures" class=""> But I cannot find a solution to
obtain real degeneracies and I could not find discussions
about this issue in the literature or in the forum.</span></div>
<div style="margin: 0px; font-size: 11px; line-height: normal;
font-family: Menlo; background-color: rgb(255, 255, 255);
min-height: 13px;" class="">
<span style="font-variant-ligatures: no-common-ligatures"
class=""></span><br class="">
</div>
<div style="margin: 0px; font-size: 11px; line-height: normal;
font-family: Menlo; background-color: rgb(255, 255, 255);"
class="">
<span style="font-variant-ligatures: no-common-ligatures"
class="">Are there approaches to solve this problem? How can
one symmetrize H(q)? Can one impose some conditions on H(R)
(the Hamiltonian in real space) such that H(q) presents the
correct symmetries?</span></div>
</blockquote>
In general yes, look at the work of R. Sakuma <span
class="doi-field"><a class="moz-txt-link-freetext" href="https://doi.org/10.1103/PhysRevB.87.235109">https://doi.org/10.1103/PhysRevB.87.235109</a> on
symmetry-adapted MLWF and examples 21-22 of the latest W90
release.<br>
<br>
HTH,<br>
<br>
Antimo<br>
</span><br>
<pre class="moz-signature" cols="72">--
Antimo Marrazzo
Doctoral Assistant
EPFL STI IMX THEOS
ME-D2 1019 (Bātiment ME)
Station 9
CH-1015 Lausanne (Switzerland)</pre>
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