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Dear all,
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<div>there are cases (typically, magnetic systems, especially with hybrids or dft+u) where there are different local/global minima, and one can randomly converge in one or the other. All are numerically correct self consistent states.</div>
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<div>And there are rare cases where, if no noise is there at start (that’s why good to use atomic plus random) some eigenstates at some kpoints are missed, leading to an incorrect minimum.</div>
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<div>Otherwise, there shouldn’t be meaningful differences, especially if one dies a restart with one/few iteration(s) after a very large cell relaxation, to account for the change of volume and the consequent change of plane wave basis.</div>
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<div>HTH</div>
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<div>nicola</div>
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<div dir="ltr">Sent from a tiny keyboard... Contact info:
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<div>http://theos-wiki.epfl.ch/Main/Contact</div>
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<blockquote type="cite">On 28 Aug 2026, at 09:04, 박기명 <knppkm@naver.com> wrote:<br>
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<span style="color: rgb(11, 11, 11); font-family: "Malgun Gothic", "맑은 고딕", sans-serif; font-size: 14px; white-space: pre-wrap;">In very rare cases, setting
</span><span style="color: rgb(11, 11, 11); font-family: "Malgun Gothic", "맑은 고딕", sans-serif; font-size: 14px; white-space: pre-wrap; font-weight: bold;">&ELECTRONS startingwfc = 'random'</span><span style="color: rgb(11, 11, 11); font-family: "Malgun Gothic", "맑은 고딕", sans-serif; font-size: 14px; white-space: pre-wrap;">
can lead to a different converged value. Have you checked that the inputs are identical?</span></div>
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<span style="color: rgb(11, 11, 11); font-family: "Malgun Gothic", "맑은 고딕", sans-serif; font-size: 14px; white-space: pre-wrap;">Also, did you set conv_thr tight enough? The default value is not good enough.</span><span style="color: rgb(11, 11, 11); font-family: "Malgun Gothic", "맑은 고딕", sans-serif; font-size: 14px; white-space: pre-wrap;">
And in my case, I only trust the total energy down to the sixth decimal place. The unit is eV.</span></div>
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<span style="font-family:"Malgun Gothic", "맑은 고딕", sans-serif;font-size:14px">Best regards,</span></div>
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<span style="font-family:"Malgun Gothic", "맑은 고딕", sans-serif;font-size:14px">GiMyung Park</span></div>
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<span style="font-family:"Malgun Gothic", "맑은 고딕", sans-serif;font-size:14px">Yonsei University</span></div>
<p style="font-size:10pt;font-family:sans-serif;padding:0 0 0 10pt"><span>-----Original Message-----</span><br>
<b>From:</b> "Simon Michnowicz via users"<users@lists.quantum-espresso.org> <br>
<b>To:</b> <users@lists.quantum-espresso.org>; <br>
<b>Cc:</b> <br>
<b>Sent:</b> 2026-08-28 (금) 10:52:09 (GMT+09:00)<br>
<b>Subject:</b> [QE-users] Result precision across different builds<br>
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<div>Dear User List</div>
<div>I am helping a researcher install Quantum Espresso. I find different combinations of compilers/libraries produce slightly different results upon a sample input given to me. The researcher said the results should be consistent up to 5 decimal points. Is
the variation that I see to be expected, or could there some other problem here?</div>
<div><br>
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<div>Tool Final Energy</div>
<div>Intel Compiler,MKL -314.1147158171</div>
<div>gcc/15.2.0-gcc-11.5.0/MKL -314.1256316418</div>
<div>gcc/11.4/openblas -314.1256341822</div>
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<div>much thanks</div>
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<div dir="ltr"><span style="font-family:arial narrow,sans-serif"><span style="font-size:12.8px"><b>---<br>
Simon Michnowicz </b> </span><br>
Senior Application Specialist, <span style="font-size:13px;border-collapse:collapse">
High-Performance Computing</span></span></div>
<span style="font-family:arial narrow,sans-serif"><span style="font-size:13px;border-collapse:collapse"><br>
<div dir="ltr"><b>Monash eResearch Centre</b></div>
<div dir="ltr">Monash University</div>
<div dir="ltr">15 Innovation Walk, Building 75, Clayton Campus</div>
<div dir="ltr">Wellington Road, VIC 3800</div>
<div dir="ltr">Australia</div>
</span></span>
<div dir="ltr"><span style="font-family:arial narrow,sans-serif"><br>
</span></div>
<div dir="ltr"><span style="font-family:arial narrow,sans-serif">T: <span>+61 3 9902 0794</span>
<br>
</span></div>
<div dir="ltr"><span style="font-family:arial narrow,sans-serif">M: <span>+61 3 0418 302 046</span></span></div>
<div dir="ltr"><span style="font-family:arial narrow,sans-serif">E: <a href="mailto:simon.michnowicz@monash.edu" target="_blank" rel="noreferrer noopener">
simon.michnowicz@monash.edu</a></span></div>
<div dir="ltr"><span style="font-family:arial narrow,sans-serif"><a href="http://monash.edu/" target="_blank" rel="noreferrer noopener">monash.edu</a></span></div>
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