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<p>Dear Rameswar Bhattacharjee</p>
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<p>To compute the Berry phase you can use WannierTool (<a href="http://www.wanniertools.com/" class="x_OWAAutoLink" id="LPlnk351356">http://www.wanniertools.com/</a>) or Z2Pack
<a href="https://z2pack.greschd.ch/en/latest/" class="x_OWAAutoLink">(https://z2pack.greschd.ch/en/latest/</a>) as post processing of QE.
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<p>The Zak phase is nothing else that Berry phase along a line, so you should be able to do it as well, but not sure how these programs perform the integration, so check carefully!</p>
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<p>Hope this help.<br>
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<p>Best regards</p>
<p>Chiara Cignarella</p>
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<p>PhD student <br>
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<p>THEOS, EPFL<br>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Da:</b> users <users-bounces@lists.quantum-espresso.org> per conto di Rameswar Bhattacharjee <rb1820@georgetown.edu><br>
<b>Inviato:</b> mercoledì 15 novembre 2023 03:08:08<br>
<b>A:</b> Quantum ESPRESSO users Forum<br>
<b>Oggetto:</b> [QE-users] Zak Phase (Z2 invariant) computation</font>
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<div class="PlainText">Hi Everyone,<br>
Can anyone in this forum suggest to me how to compute the Z2 invariant<br>
of Zak Phases to determine the nature of the topological phase?<br>
<br>
The Z2 value can be 0 or pi but I am not sure if we can compute this in QE.<br>
<br>
Any suggestion would be appreciated. Thanks in advance.<br>
<br>
Thanks<br>
<br>
<br>
-- <br>
Rameswar Bhattacharjee<br>
Georgetown University<br>
Washington, DC 20057<br>
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