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<p class="MsoNormal">Thanks Mostafa,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I tried both options, but continue to have convergence issues. I repeated the check with up to 8 x 8 x 8 k-points to some sense (but not to the threshold) of convergence (0.0x Ry at about 100 iterations), but larger than that the memory
requirements overshoot > 256 GB).<o:p></o:p></p>
<p class="MsoNormal">CG diagonalization also doesn’t help.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Ends in same large scf error divergence quickly. I have attached one of the runs’ “in and out” here.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am trying a finer k-point mesh 12x12x12 and a bit larger smearing with 3x3x3 cell now to see if as discussed in some other threads to avoid issues with occupation states.<o:p></o:p></p>
<p class="MsoNormal">I have been perusing literature and see some where even 2 x 2 x 2 cells work for some (I do note that not many are for metallic systems), but there are studies on Fe, NI and W where even 2x2x2 or 3x3x3 super cell seem to work.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Not sure what I am missing. Any thoughts?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Tejas<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> users <users-bounces@lists.quantum-espresso.org>
<b>On Behalf Of </b>Mostafa Youssef via users<br>
<b>Sent:</b> Saturday, January 9, 2021 03:48 PM<br>
<b>To:</b> users@lists.quantum-espresso.org<br>
<b>Subject:</b> [QE-users] Convergence with interstitials<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">Dear Tejas,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">I see two issues:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">1) Your supercell size is too small. This corresponds to a high concentration of N. I would go for 4x4x4 conventional cells of W. That is 128 atoms.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">2) A magnetic moment on N is needed since the odd number of electrons is because of N.
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">Regards,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">Mostafa<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Verdana",sans-serif">AUC<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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