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Dear professor Marzari and Changpeng,</div>
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<br>
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Thanks for the valuable information.</div>
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<br>
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I will have a look at these options.</div>
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Regards <br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="line-height: 1.6; font-size: 11pt; color: rgb(0, 0, 0);" face="Calibri, sans-serif"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Changpeng Lin via users <users@lists.quantum-espresso.org><br>
<b>Sent:</b> Wednesday, October 25, 2023 1:25 PM<br>
<b>To:</b> users@lists.quantum-espresso.org <users@lists.quantum-espresso.org><br>
<b>Subject:</b> Re: [QE-users] Born Huang and Huang invariance conditions</font>
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<div style="font-family:Helvetica,Helvetica,微软雅黑,宋体">Yes, it’s implemented in matdyn, as the Invariance conditions are made on real-space force constants. For q2r, there is a related tag “write_lr” due to this implementation, to deal with the subtlety of long-range
interactions in polar solids.</div>
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<div style="font-family:Helvetica,Helvetica,微软雅黑,宋体">One can find an example input in QE test suite for 2D phonon calculations with those corrections:</div>
<div style="font-family:Helvetica,Helvetica,微软雅黑,宋体"><a href="https://gitlab.com/QEF/q-e/-/tree/develop/test-suite/ph_2d" data-auth="NotApplicable" id="OWA75e8e572-050d-90f3-c916-77b27a7f8772" class="OWAAutoLink">https://gitlab.com/QEF/q-e/-/tree/develop/test-suite/ph_2d</a> <br>
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<div style="font-family:Helvetica,Helvetica,微软雅黑,宋体">Best,</div>
<div style="font-family:Helvetica,Helvetica,微软雅黑,宋体">Changpeng</div>
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>From </td>
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<a href="mailto:nicola.marzari@epfl.ch" class="x_mail-from OWAAutoLink" style="text-decoration: none; color: rgb(48, 97, 242);" id="OWAe33c7866-d00c-13e3-9924-0f22ea6b3df0">Nicola Marzari<nicola.marzari@epfl.ch>
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Date </td>
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10/25/2023 17:02 </td>
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To </td>
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<a href="mailto:users@lists.quantum-espresso.org" class="x_mail-to OWAAutoLink" style="text-decoration: none; color: rgb(48, 97, 242);" id="OWA847add24-8681-d6e9-5536-4e8bee7d23c3"><users@lists.quantum-espresso.org> ,<br>
</a><a href="mailto:changpeng.lin@epfl.ch" class="x_mail-to OWAAutoLink" style="text-decoration: none; color: rgb(48, 97, 242);" id="OWAe97b6d0e-2fac-c86f-ea11-4bda1e3c2597">Changpeng Lin<changpeng.lin@epfl.ch>
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Re: [QE-users] Born Huang and Huang invariance conditions </td>
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Thanks - thhis is the paper:<br>
<br>
https://www.nature.com/articles/s41524-022-00920-6<br>
<br>
and in the matdyn <br>
(https://www.quantum-espresso.org/Doc/INPUT_MATDYN.html) this is the <br>
option 'all'.<br>
<br>
Not sure about q2r - should be there as well, but I do not see it - but <br>
maybe I'm missing something?<br>
<br>
nicola<br>
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<br>
On 25/10/2023 16:44, Elio Physics wrote:<br>
<blockquote class="x_mmbqc1">Dear all,<br>
<br>
There have been several papers discussing the use of the so-called <br>
Born-Huang and Huang invariance conditions to soothe the possible <br>
negative frequencies that may arise in the long wavelength limit (q->0, <br>
near the G point) in the phonon dispersion of 2D and 1D material.<br>
<br>
Is there a specific flag in the ph.x input file that needs to be turned <br>
on to incorporate such corrections?<br>
<br>
Regards<br>
<br>
Elie Moujaes<br>
Adjunct professor level 4<br>
Federal University of Rondonia<br>
Brazil<br>
<br>
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<br>
-- <br>
----------------------------------------------------------------------<br>
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL<br>
Director, National Centre for Competence in Research NCCR MARVEL, SNSF<br>
Head, Laboratory for Materials Simulations, Paul Scherrer Institut<br>
Contact info and websites at http://theossrv1.epfl.ch/Main/Contact<br>
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