<DIV>Dear Haruhiko&nbsp;Dekura<BR><BR>&gt;Message:&nbsp;3<BR>&gt;Date:&nbsp;Wed,&nbsp;30&nbsp;Dec&nbsp;2009&nbsp;01:30:28&nbsp;+0900<BR>&gt;From:&nbsp;Haruhiko&nbsp;Dekura&nbsp;&lt;dekura@cmp.sanken.osaka-u.ac.jp&gt;<BR>&gt;Subject:&nbsp;Re:&nbsp;[Pw_forum]&nbsp;about&nbsp;fermi&nbsp;level<BR>&gt;To:&nbsp;PWSCF&nbsp;Forum&nbsp;&lt;pw_forum@pwscf.org&gt;<BR>&gt;Message-ID:<BR>&gt;        &lt;B22CEA00-6D59-4FF1-8B8E-DBC4F48E4CF3@cmp.sanken.osaka-u.ac.jp&gt;<BR>&gt;Content-Type:&nbsp;text/plain;&nbsp;charset=us-ascii<BR>&gt;<BR>&gt;Dear&nbsp;Wang&nbsp;<BR>&gt;<BR>&gt;I&nbsp;think&nbsp;that&nbsp;the&nbsp;Fermi level&nbsp;obtained&nbsp;with&nbsp;nscf&nbsp;run&nbsp;reaches&nbsp;sufficient&nbsp;value&nbsp;only&nbsp;when&nbsp;the&nbsp;KS&nbsp;energy&nbsp;spectrum&nbsp;(&nbsp;hence,&nbsp;also&nbsp;scf-potential&nbsp;)&nbsp;is&nbsp;well&nbsp;converged&nbsp;in&nbsp;scf&nbsp;calculation.&nbsp;</DIV>
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<DIV>How to judge the KS energy spectrum is well converged or not&nbsp;in scf calculation ? </DIV>
<DIV>Can you give me special examples or make some elaborate on this ? what should I do when encounter this problem ?</DIV>
<DIV>I found many pwscf users encounter the same problem and they don't know which fermi level is used to plot DOS when fermi level is different between scf.out and nscf.out.</DIV>
<DIV>Thank you very much for you help !</DIV>
<DIV><BR>&gt;Therefore,&nbsp;in&nbsp;my&nbsp;guess,&nbsp;if&nbsp;you&nbsp;can&nbsp;see&nbsp;the&nbsp;convergence&nbsp;of&nbsp;KS&nbsp;levels&nbsp;as&nbsp;well&nbsp;as&nbsp;total&nbsp;energy&nbsp;against&nbsp;the&nbsp;increase&nbsp;of&nbsp;k-point&nbsp;(and&nbsp;width&nbsp;of&nbsp;smearing),&nbsp;the&nbsp;Fermi-level&nbsp;obtained&nbsp;with&nbsp;DOS&nbsp;calculation&nbsp;is&nbsp;more&nbsp;reliable&nbsp;value.&nbsp;So,&nbsp;I&nbsp;think&nbsp;the&nbsp;problem&nbsp;is&nbsp;depending&nbsp;on&nbsp;the&nbsp;convergency&nbsp;of&nbsp;your&nbsp;scf-potential&nbsp;after&nbsp;scf&nbsp;calculation.&nbsp;If&nbsp;you&nbsp;don't&nbsp;have&nbsp;converged&nbsp;one,&nbsp;&nbsp;both&nbsp;Fermi-levels&nbsp;(&nbsp;obtained&nbsp;by&nbsp;scf&nbsp;or&nbsp;nscf&nbsp;run)&nbsp;so&nbsp;obtained&nbsp;are&nbsp;both&nbsp;not&nbsp;sufficient.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<BR>&gt;What&nbsp;do&nbsp;you&nbsp;think&nbsp;?<BR>&gt;<BR>&gt;<BR>&gt;Haruhiko&nbsp;Dekura<BR>&gt;<BR>&gt;PH.D.&nbsp;student<BR>&gt;Osaka&nbsp;university&nbsp;<BR>&gt;<BR>&gt;<BR>&gt;On&nbsp;2009/12/29,&nbsp;at&nbsp;23:51,&nbsp;Q.J.Wang&nbsp;wrote:<BR>&gt;<BR>&gt;&gt;&nbsp;Dear&nbsp;all<BR>&gt;&gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After&nbsp;I&nbsp;run&nbsp;scf(k-points,3*3*3)with&nbsp;'smearing'&nbsp;&nbsp;,&nbsp;I&nbsp;increase&nbsp;the&nbsp;k-points&nbsp;(5*5*5)and&nbsp;run&nbsp;nscf&nbsp;with&nbsp;'tetrahedra'&nbsp;in&nbsp;order&nbsp;to&nbsp;get&nbsp;DOS,but&nbsp;the&nbsp;fermi&nbsp;levels&nbsp;have&nbsp;little&nbsp;difference&nbsp;between&nbsp;the&nbsp;scf.out&nbsp;and&nbsp;nscf.out&nbsp;.&nbsp;Which&nbsp;I&nbsp;should&nbsp;select&nbsp;when&nbsp;plot&nbsp;DOS&nbsp;pictuce&nbsp;?<BR>&gt;&gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I&nbsp;have&nbsp;search&nbsp;in&nbsp;the&nbsp;forum&nbsp;,but&nbsp;still&nbsp;haven't&nbsp;the&nbsp;correct&nbsp;answer&nbsp;.<BR><BR>--<BR></DIV>
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<DIV>Best regards</DIV>
<DIV>&nbsp;</DIV>
<DIV>Q.J.Wang</DIV>
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<DIV>XiangTan University </DIV></DIV><br><br><span title="neteasefooter"/></span>