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</o:shapelayout></xml><![endif]--></head><body lang=ZH-TW link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US style='font-family:"Calibri","sans-serif";color:#1F497D'>Providing the structure built is correct, then your energy cutoff set is too low.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Calibri","sans-serif";color:#1F497D'>I would suggest, go for something like ecutwfc = 80; ecutrho = 4*ecutwfc<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Calibri","sans-serif";color:#1F497D'>Geoffrey<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> pw_forum-bounces@pwscf.org [mailto:pw_forum-bounces@pwscf.org] <b>On Behalf Of </b>Pallavi Bothra<br><b>Sent:</b> 2014</span><span style='font-size:11.0pt'>年</span><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>6</span><span style='font-size:11.0pt'>月</span><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>27</span><span style='font-size:11.0pt'>日</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><span style='font-size:11.0pt'>下午</span><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> 06:09<br><b>To:</b> pw_forum@pwscf.org<br><b>Subject:</b> [Pw_forum] convergence problem<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><div><div><div><div><div><div><div><p class=MsoNormal><span lang=EN-US>Dear all,<o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US> I am trying to do a scf calculation considering spin-orbit interaction. Here is the input file:<br><br>&CONTROL<br> calculation = 'scf',<br> restart_mode='from_scratch',<br> prefix='BiTe',<br> pseudo_dir = './',<br> outdir='./tempc',<br> nstep = 500<br> /<br> &system<br> ibrav= 0,<br> nat= 40,<br> ntyp= 2,<br> celldm(1) = 1.890359168,<br> ecutwfc = 30.0,<br> ecutrho= 300.0,<br> occupations='smearing',<br> degauss = 0.01 ,<br> smearing = 'cold' ,<br> starting_magnetization(1) = 0.5<br> starting_magnetization(2) = 0.5<br> noncolin = .true.<br> lspinorb = .true.<br> <br>/<br> &ELECTRONS<br> electron_maxstep = 500 ,<br> conv_thr = 1.0d-10<br> mixing_beta = 0.1 ,<br> mixing_mode = 'local-TF',<br> mixing_ndim = 10 ,<br>/<br> &IONS<br> upscale = 100 ,<br><br><br>/<br><br>CELL_PARAMETERS<br>8.7900000 0.00000000 0.00000000<br>-4.3950000 7.6123633 0.00000000<br>0.00000000 0.00000000 36.64000000<br><br>ATOMIC_SPECIES<br>Te 127.6 Te.rel-pbe-dn-rrkjus_psl.0.2.2.UPF<br>Bi 208.980 Bi.pbe-d-mt.UPF<br><br>ATOMIC_POSITIONS angstrom<br>Te 0.001076915 -0.001111167 24.534365287<br>Bi 0.000000000 0.000000000 12.190002400 0 0 0<br>Te 2.197500000 1.268727220 10.146666670 0 0 0<br>Te -0.001767560 2.537644595 20.687693846<br>Te 0.000000000 0.000000000 6.383268000 0 0 0<br>Te 2.197537577 1.265453382 16.833926576<br>Te -0.000000000 2.537454430 13.910065330 0 0 0<br>----------------------------<br>K_POINTS automatic<br>4 4 1 0 0 0<o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US>Actually first I have relaxed the structure w/o considering spin-orbit interaction. Then I used the optimised coordinates to do the scf calculation but the system did not converge even after 300 cycles.<o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US>Thank you in advance<o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-US>Regards<o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-US>Pallavi Bothra<o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-US>JNCASR, Bangalore<o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-US>India<o:p></o:p></span></p><div><div><div><div><div><div><div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div></div></div></div></div></div></div></div></div></body></html>