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Hello</div>
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There has been a nasty bug in local-TF</div>
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I'm not sure if it was already there in 6.5, but it's worth trying with a recent version of the code (7.3.1 or 7.4.1). </div>
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I hope it helps solve the problem.</div>
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Pietro</div>
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<div dir="ltr" id="divRplyFwdMsg"><span style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Giovanni Cantele <giovanni.cantele@spin.cnr.it><br>
<b>Sent:</b> Wednesday, May 28, 2025 12:18<br>
<b>To:</b> Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org><br>
<b>Subject:</b> Re: [QE-users] YBCO (001) slabs: "convergence" problem</span>
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<div style="direction: ltr;">Dear Michele,</div>
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</div>
<div style="direction: ltr;">I have had the time for just a quick inspection to your files, and unfortunately I did not find possible mistakes.</div>
<div style="direction: ltr;">Maybe someone else will be more helpful in this regard.</div>
<div style="direction: ltr;">Both the total energy and the total force in the output are monotonically decreasing, with the exception of the</div>
<div style="direction: ltr;">4th relaxation step.</div>
<div style="direction: ltr;">The only thing that might be odd (but it could be correct for the system you're studying) is that the</div>
<div style="direction: ltr;">comparison of the initial and the latest structure shows only an outwards relaxation of the topmost and lowest atomic</div>
<div style="direction: ltr;">layers.</div>
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</div>
<div style="direction: ltr;">I can just suggest at the moment to restart from scratch a calculation in which you use as initial</div>
<div style="direction: ltr;">positions the latest (or the ones before the latest) printed by the code. It shouldn't change anything in principle, but</div>
<div style="direction: ltr;">there have been several cases in my experience in which that properly worked, as if at some point of the structural optimization the</div>
<div style="direction: ltr;">starting charge density were for some reason "wrong" or "inappropriate" (even if coming from the previous steps), and</div>
<div style="direction: ltr;">restarting from atomic/random wave functions prevents the code from remaining stuck. However, I don't have a clear explanation for that</div>
<div style="direction: ltr;">if not that this recipe has worked for me! </div>
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<div style="direction: ltr;">Giovanni</div>
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<div style="direction: ltr;"><span style="color: rgb(0, 0, 0);">-- <br>
<br>
Giovanni Cantele, PhD<br>
CNR-SPIN<br>
c/o Dipartimento di Fisica<br>
Universita' di Napoli "Federico II"<br>
Complesso Universitario M. S. Angelo - Ed. 6<br>
Via Cintia, I-80126, Napoli, Italy<br>
</span><span style="color: rgb(17, 85, 204);"><a href="mailto:giovanni.cantele@spin.cnr.it" id="OWA997ef90f-4112-ae7f-a8a8-441a06ff89b9" class="OWAAutoLink" style="color: rgb(17, 85, 204);">e-mail: giovanni.cantele@spin.cnr.it</a></span><span style="color: rgb(0, 0, 0);"><br>
Phone: +39 081 676910<br>
Skype contact: giocan74<br>
<br>
ResearcherID: </span><span style="color: rgb(17, 85, 204);"><a href="http://www.researcherid.com/rid/A-1951-2009" id="OWAcfddc2ec-0249-701c-9b51-6502a4729531" class="OWAAutoLink" style="color: rgb(17, 85, 204);" data-auth="NotApplicable">http://www.researcherid.com/rid/A-1951-2009</a></span><span style="color: rgb(0, 0, 0);"><br>
Web page: </span><span style="color: rgb(17, 85, 204);"><a href="https://sites.google.com/view/giovanni-cantele/home" id="OWAfab5b3e8-0c33-53bc-93f0-d82a3a671e66" class="OWAAutoLink" style="color: rgb(17, 85, 204);" data-auth="NotApplicable">https://sites.google.com/view/giovanni-cantele/home</a></span></div>
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<div style="direction: ltr;">Il giorno mer 28 mag 2025 alle ore 11:23 michele de angelis <<a href="mailto:michele.deangelis.01@alumni.uniroma2.eu" id="OWA14d12db6-6eac-61f4-12ed-dc0f182c380e" class="OWAAutoLink">michele.deangelis.01@alumni.uniroma2.eu</a>>
ha scritto:</div>
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<span style="background-color: rgb(244, 244, 244);"><a href="https://uniroma2-my.sharepoint.com/:u:/g/personal/michele_deangelis_01_alumni_uniroma2_eu/EdqwsiZzdStJhJGXaYDSIOsB0WUkus6riva9xFNK4dvGrw" id="OWA4a11ef74-fde3-f0c6-1451-0809fbc63445" class="OWAAutoLink" style="padding-right: 1px; padding-left: 1px; background-color: rgb(244, 244, 244); border-radius: 2px;" data-auth="NotApplicable"><img style="width: 16px; height: 16px; padding-top: 1px; padding-right: 2px; padding-bottom: 2px;" width="16" height="16" src="https://res-1.cdn.office.net/assets/mail/file-icon/png/generic_16x16.png">YBCO_001_CuO2_2layers.in</a><a href="https://uniroma2-my.sharepoint.com/:u:/g/personal/michele_deangelis_01_alumni_uniroma2_eu/EWwLUiRWxFxLiOe-okzTGBkBJ5sQt7QCPbjEqCaKYWBDQA" id="OWA0639bf7b-78bf-720f-56e5-99bb97065ec0" class="OWAAutoLink" style="padding-right: 1px; padding-left: 1px; background-color: rgb(244, 244, 244); border-radius: 2px;" data-auth="NotApplicable"><img style="width: 16px; height: 16px; padding-top: 1px; padding-right: 2px; padding-bottom: 2px;" width="16" height="16" src="https://res-1.cdn.office.net/assets/mail/file-icon/png/generic_16x16.png">YBCO_001_CuO2_2layers.out</a></span>
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Dear all,<br>
I am trying to relax YBCO (001) slabs with symmetric terminations (same on both sides) and a vacuum spacing of 7.5 Å on each side (7.5 Å – slab – 7.5 Å). I have tested all four possible surface terminations of YBCO, but none of the relaxations converge properly.
After m SCF cycles and n BFGS cycles, the SCF calculation starts to exceed 100 iterations.<br>
Moreover, the total energy values reported in the output file do not show a monotonic trend but oscillate instead. In contrast, the total force does decrease, from 0.9 down to about 0.09. I am using PBE-PAW pseudopotentials with the GGA approximation. The initial
geometry has been carefully verified.<br>
Spin and polarization effects are not included, as the slabs are symmetric. I have attempted several adjustments to improve convergence, including:<br>
- Reducing mixing_beta to 0.1</div>
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- Increasing degauss to 0.05 and changing the smearing type<br>
- Setting mixing_mode = 'local-TF'<br>
- Switching the diagonalization method to cg</div>
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However, the problem persists.<br>
Could you kindly help me understand what might be going wrong? My input and output files are attached below for reference.<br>
Thank you in advance for your support.</div>
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Best regards, </div>
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Michele De Angelis </div>
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PhD student, Dept. of Chemical Sciences and Technologies, Univesity of Rome Tor Vergata (Italy)</div>
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