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<div class="moz-cite-prefix">On 15/03/2023 07:14, zhouchao via users
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:tencent_BE336644C46B53B753FA193533175FFD9206@qq.com">
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<div>How to deal with a mode of phonon spectrum that cannot
converge, how to make it converge, tried many methods, but can
not be solved。</div>
<div>how to explain this problem, what is the reason, is it a
problem of the structure itself, how to analyze it?</div>
</blockquote>
<p>This output line give a suggestion:</p>
<p><span style="font-family:monospace"><span
style="color:#000000;background-color:#ffffff;">Possibly too
few bands at point 1 0.00000 0.00000 0.00000</span><br>
<br>
</span>your scf calculation has been done with 23 electronic bands
(Kohn-Sham states), but it may not be enough for the phonon
caculaiton. Try to increase this value a bit in the pw.x input</p>
<p>You can also try to increase nmix_ph, as hinted in the manual, to
20.</p>
<p>Finally, you can and decrease alpha_mix, and add a few more
iterations of mixing, i.e.</p>
<p>alpha_mix = 0.3, 0.1, 0.05, 0.01<br>
</p>
<p><br>
</p>
<p>hth<br>
</p>
<p><br>
</p>
<p><br>
</p>
<blockquote type="cite"
cite="mid:tencent_BE336644C46B53B753FA193533175FFD9206@qq.com">
<div>As shown in the end of the attachment, the first 10 modes all
converge, but the 11th mode fails to converge.</div>
<br>
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</blockquote>
<div class="moz-signature">-- <br>
<small>Dr. Lorenzo Paulatto<br>
IdR @ IMPMC - CNRS UMR 7590 & Sorbonne Université<br>
phone: +33 (0)1 442 79822 / skype: paulatz<br>
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