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<p>I agree that using scf_must_converge=.false. is not the best
solution if you start with it without testing! But the question
was why the calculation stopped after 80 iterations. The default
for electron_maxstep is 100 and who knows maybe it was stopped too
soon and it would have converged at 92. In any case it stopped
because it was told to stop at 80 iterations. Why it didn't reach
convergence is another matter.</p>
<p><br>
</p>
<p>Using scf_must_converge=.false. is not that bad if you test the
system beforehand. There are systems that will not converge in the
first step and then the algorithm moves the atoms a bit and then
convergence is achieved as it should. <br>
</p>
<p><br>
</p>
<p>All the best,</p>
<p><br>
</p>
<p>Lucian<br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 20/07/2022 22:26, Tiana, Davide
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:DB7PR02MB4236156728E3B31729C3E74BEB8E9@DB7PR02MB4236.eurprd02.prod.outlook.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<style type="text/css" style="display:none;">P {margin-top:0;margin-bottom:0;}</style>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
That (using scf_must_converge=.false. is a very vary bad advice.
If the system is not converging after 80 iterations most likely
there's something wrong. This could be the pseudo, the geometry,
or any thing.</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
You should check the convergence rate between each step and see
if it fluctuate and of how much. Then, maybe it is almost
converged so you simply need to extend the number of cycles from
80 to 100 or 150. </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Last but not least, you can know if it's not converging because
your threshold is too tight, or it's not converging at all. If
the latter you need to find why. By using <span
style="background-color:rgb(255, 255, 255);display:inline
!important">scf_must_converge=.false. you'll simply risk to
end in a wrong state. </span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
All the best</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Davide </div>
<div class="BodyFragment"><font size="2"><span
style="font-size:11pt">
<div class="PlainText">------------------------------<br>
<br>
Message: 3<br>
Date: Wed, 20 Jul 2022 10:40:09 +0300<br>
From: "Lucian D. Filip" <a class="moz-txt-link-rfc2396E" href="mailto:lucian.filip@infim.ro"><lucian.filip@infim.ro></a><br>
To: <a class="moz-txt-link-abbreviated" href="mailto:users@lists.quantum-espresso.org">users@lists.quantum-espresso.org</a><br>
Subject: Re: [QE-users] relax : convergence NOT achieved
after 80<br>
iterations: stopping<br>
Message-ID:
<a class="moz-txt-link-rfc2396E" href="mailto:85bedcbc-8cde-3bad-ba05-2e38d6e80063@infim.ro"><85bedcbc-8cde-3bad-ba05-2e38d6e80063@infim.ro></a><br>
Content-Type: text/plain; charset="utf-8"; Format="flowed"<br>
<br>
here is the problem! you told QE to only do 80 iterations
in a scf step.<br>
After the 80 iterations there was no convergence and the
calculation<br>
stopped. If you want it to continue to the next step and
let QE move the<br>
atoms even if the first scf iteration did not converge you
should use<br>
the following flag together with the electron_maxstep:<br>
<br>
scf_must_converge = .false.<br>
<br>
--<br>
*Dr. Lucian Dragos Filip*<br>
National Institute of Materials Physics<br>
Atomistilor str. 405A, PO Box MG. 7<br>
Magurele, 077125<br>
Bucharest, Romania<br>
E-mail: <a class="moz-txt-link-abbreviated" href="mailto:lucian.filip@infim.ro">lucian.filip@infim.ro</a><br>
Website: <a href="https://lucianfilip.wordpress.com/"
data-auth="NotApplicable" moz-do-not-send="true"
class="moz-txt-link-freetext">https://lucianfilip.wordpress.com/</a><br>
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<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (<a class="moz-txt-link-abbreviated" href="http://www.max-centre.eu">www.max-centre.eu</a>)
users mailing list <a class="moz-txt-link-abbreviated" href="mailto:users@lists.quantum-espresso.org">users@lists.quantum-espresso.org</a>
<a class="moz-txt-link-freetext" href="https://lists.quantum-espresso.org/mailman/listinfo/users">https://lists.quantum-espresso.org/mailman/listinfo/users</a></pre>
</blockquote>
<div class="moz-signature">-- <br>
<b>Dr. Lucian Dragos Filip</b><br>
National Institute of Materials Physics<br>
Atomistilor str. 405A, PO Box MG. 7<br>
Magurele, 077125<br>
Bucharest, Romania<br>
E-mail: <url><a class="moz-txt-link-abbreviated" href="mailto:lucian.filip@infim.ro">lucian.filip@infim.ro</a></url><br>
Website: <url><a class="moz-txt-link-freetext" href="https://lucianfilip.wordpress.com/">https://lucianfilip.wordpress.com/</a></url><br>
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