<html><head><style>p{margin-top:0px;margin-bottom:0px;}</style></head><body><div style="font-size:14px; font-family:Gulim,굴림,sans-serif;"><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><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><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><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><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><br></div><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><span style="font-family:"Malgun Gothic", "맑은 고딕", sans-serif;font-size:14px">Best regards,</span></div><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><span style="font-family:"Malgun Gothic", "맑은 고딕", sans-serif;font-size:14px">GiMyung Park</span></div><div style="font-family: Gulim, 굴림, sans-serif; font-size: 14px; letter-spacing: -0.5px; background-color: rgb(255, 255, 255);"><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><br></p><div dir="ltr"><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></div><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><div><br></div><div>much thanks</div><div><br></div><div><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><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></div></div></div></div></div></div></div></div></div></div></div></div>
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