<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">PS. Start practicing with a small unit cell that you can draw with your hands. Get familiar with the numerical parameters (thresholds, cutoffs, etc.) in that case and develop your feeling on what happens when you change each of them. Starting with examples provided with the distribution may be a good idea. Then, but only then, try more complex (and possibly meaningful) cases. Above all, do not do anything that you do not understand, no matter who recommends that. Good luck! SB<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 14 May 2020, at 17:32, Stefano Baroni <<a href="mailto:baroni@sissa.it" class="">baroni@sissa.it</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Fariba: luck is no substitute for practice & understanding.<br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">On 14 May 2020, at 16:34, Fariba Islam <<a href="mailto:ezqhaz@gmail.com" class="">ezqhaz@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">Initially it was 1e-8 but nscf calculation was crashing. So I searched for a solution and in ResearchGate I found that in order to solve this I need to decrease conv threshold or increase ecutwfc. That is why I increased it to such high values gradually. But didn’t have any luck.<br class=""><br class="">On Thursday, May 14, 2020, Stefano de Gironcoli <<a href="mailto:degironc@sissa.it" class="">degironc@sissa.it</a>> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div text="#000000" bgcolor="#FFFFFF" class=""><p class=""><tt class="">do you really need conv_thr=1e-20 ?</tt></p><p class=""><tt class="">stefano</tt><br class="">
    </p>
    <div class="">On 14/05/20 09:18, Fariba Islam wrote:<br class="">
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    <blockquote type="cite" class="">
      
      <div dir="ltr" class="">Dear all,
        <div class="">My  conv_thr=1e-20 and ecutwfc=200 ecutrho=800</div>
        <div class="">My nscf calculation is crashing with the error </div>
        <div class=""><br class="">
        </div>
        <div class="">task #        10<br class="">
               from c_bands : error #         1<br class="">
               too many bands are not converged</div>
        <div class=""><font color="#222222" class=""><br class="">
          </font></div>
        <div class=""><font color="#222222" class="">How can I solve? From suggestions
            found online, I have reduced the threshold and increased
            ecutwfc and ecutrho. </font></div>
        <div class=""><font color="#222222" class="">Regards</font></div>
        <div class=""><font color="#222222" class="">Fariba Islam</font></div>
        <div class=""><font color="#222222" class="">Bangladesh University of Engineering
            and Technology</font></div>
      </div>
      <br class="">
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      <pre class="">______________________________<wbr class="">_________________
Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/quantum-espresso" target="_blank" class="">www.max-centre.eu/quantum-<wbr class="">espresso</a>)
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_______________________________________________<br class="">Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/quantum-espresso" class="">www.max-centre.eu/quantum-espresso</a>)<br class="">users mailing list <a href="mailto:users@lists.quantum-espresso.org" class="">users@lists.quantum-espresso.org</a><br class=""><a href="https://lists.quantum-espresso.org/mailman/listinfo/users" class="">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div></blockquote></div><br class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><div class=""><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><span style="font-size: 12px;" class="">— </span></div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><div style="margin: 0px;" class=""><font class="Apple-style-span"><span style="font-size: 12px;" class="">Stefano Baroni - Trieste —  </span><a href="http://stefano.baroni.me/" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-stroke-width: 0px;" class="">http://stefano.baroni.me</a><span style="font-size: 12px;" class=""> </span></font></div></div><div style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-stroke-width: 0px;" class=""><br class=""></div></div></div></div></div></div></div></span></span></div></div></div></span><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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<br class=""></div>_______________________________________________<br class="">Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/quantum-espresso" class="">www.max-centre.eu/quantum-espresso</a>)<br class="">users mailing list <a href="mailto:users@lists.quantum-espresso.org" class="">users@lists.quantum-espresso.org</a><br class=""><a href="https://lists.quantum-espresso.org/mailman/listinfo/users" class="">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div></blockquote></div><br class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><div class=""><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: normal; orphans: 2; text-indent: 0px; widows: 2; border-spacing: 0px;"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><span style="font-size: 12px;" class="">— </span></div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><div style="margin: 0px;" class=""><font class="Apple-style-span"><span style="font-size: 12px;" class="">Stefano Baroni - Trieste —  </span><a href="http://stefano.baroni.me" style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-stroke-width: 0px;" class="">http://stefano.baroni.me</a><span style="font-size: 12px;" class=""> </span></font></div></div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-stroke-width: 0px;" class=""><br class=""></div></div></div></div></div></div></div></span></span></div></div></div></span><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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