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<DIV><FONT color=#000000 size=3 face=宋体>
<DIV><SPAN style="FONT-SIZE: 13px; FONT-FAMILY: arial,sans-serif"><FONT
color=#000000 size=4>Dear Filipe,</FONT></SPAN></DIV>
<DIV><SPAN style="FONT-SIZE: 13px; FONT-FAMILY: arial,sans-serif"><FONT
color=#000000 size=4> I appreciate your
reply. It is so helpful for me. </FONT></SPAN></DIV>
<DIV><SPAN style="FONT-SIZE: 13px; FONT-FAMILY: arial,sans-serif"><FONT
color=#000000><BR><FONT size=4 face=Arial></FONT></FONT></SPAN></DIV>
<DIV><SPAN style="FONT-SIZE: 13px; FONT-FAMILY: arial,sans-serif"><FONT
color=#000000 size=4>Best Regards</FONT></SPAN></DIV></FONT></DIV>
<DIV><FONT size=4 face=Arial>JWY</FONT></DIV>
<DIV align=left><FONT color=#c0c0c0 size=2 face=Verdana>2014-04-23</FONT></DIV>
<DIV align=left><FONT size=2 face=Verdana>
<HR id=SignNameHR style="HEIGHT: 2px; WIDTH: 122px" align=left SIZE=2>
</FONT></DIV>
<DIV align=left><FONT color=#c0c0c0 size=2 face=Verdana><SPAN
id=_FlashSignName>yjunwei2012</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Verdana>
<HR>
</FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>发件人：</STRONG>Filipe Camargo Dalmatti
Alves Lima <flima@if.usp.br></FONT></DIV>
<DIV><FONT size=2
face=Verdana><STRONG>发送时间：</STRONG>2014-04-23 10:59</FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>主题：</STRONG>Re: [Pw_forum] The relax
problem</FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>收件人：</STRONG>"PWSCF
Forum"<pw_forum@pwscf.org></FONT></DIV>
<DIV><FONT size=2 face=Verdana><STRONG>抄送：</STRONG></FONT></DIV>
<DIV><FONT size=2 face=Verdana></FONT> </DIV>
<DIV><FONT size=2 face=Verdana>
<DIV dir=ltr>By looking at the total forces. There is a part in the output that
will show the forces on the atoms and the total force of the system.
<DIV><BR></DIV>
<DIV>You can grep the output using this command: cat $youroutput | grep "total
force" (or something like that, I don't remember the captcha exactly). This
number should decrease along the time. If the total force reach the threshold
condition, the calculation will stop. Otherwise it can also stop after lots of
tries and it will complain saying that the convergence didn't achieved the
mininum.</DIV>
<DIV><BR></DIV>
<DIV>For further info, the criteria for the force can be seen below:<BR></DIV>
<DIV><BR></DIV>
<DIV>
<DIV><B>etot_conv_thr</B><SPAN style="WHITE-SPACE: pre"> </SPAN>REAL</DIV>
<DIV>Default:<SPAN style="WHITE-SPACE: pre"> </SPAN>1.0D-4</DIV>
<DIV>convergence threshold on total energy (a.u) for ionic</DIV>
<DIV>minimization: the convergence criterion is satisfied</DIV>
<DIV>when the total energy changes less than etot_conv_thr</DIV>
<DIV>between two consecutive scf steps. Note that etot_conv_thr</DIV>
<DIV>is extensive, like the total energy.</DIV>
<DIV>See also forc_conv_thr - both criteria must be satisfied</DIV>
<DIV> </DIV>
<DIV><BR></DIV>
<DIV><B>forc_conv_thr</B><SPAN style="WHITE-SPACE: pre"> </SPAN>REAL</DIV>
<DIV>Default:<SPAN style="WHITE-SPACE: pre"> </SPAN>1.0D-3</DIV>
<DIV>convergence threshold on forces (a.u) for ionic minimization:</DIV>
<DIV>the convergence criterion is satisfied when all components of</DIV>
<DIV>all forces are smaller than forc_conv_thr.</DIV>
<DIV>See also etot_conv_thr (note that the latter is extensive,</DIV>
<DIV>forc_conv_thr is not) - both criteria must be satisfied</DIV>
<DIV><BR></DIV>
<DIV>source: <A
href="http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#id3119460">http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#id3119460</A></DIV>
<DIV> </DIV></DIV>
<DIV><BR></DIV>
<DIV>Regards,</DIV>
<DIV><BR></DIV>
<DIV>Filipe</DIV></DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On Tue, Apr 22, 2014 at 10:04 PM, yjunwei2012 <SPAN
dir=ltr><<A href="mailto:yjunwei2012@163.com"
target=_blank>yjunwei2012@163.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><U></U>
<DIV
style="BORDER-LEFT-WIDTH: 0px; BORDER-RIGHT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; MARGIN: 12px; LINE-HEIGHT: 1.3; BORDER-TOP-WIDTH: 0px"
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<DIV><FONT color=#000000 size=3 face=宋体>Dear manchugh，</FONT></DIV>
<DIV> Thank you for your reply! I still have some problems
and need your help. When we relax the system, how can we judge the relax
result is successful or fail? and is there have some big different
aspects between relax and vc-relax? Thank you again!</DIV>
<DIV> </DIV>
<DIV>Best wishes! </DIV>
<DIV>JWY</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV align=left><FONT color=#c0c0c0 face=Verdana>2014-04-23</FONT></DIV>
<DIV align=left><FONT face=Verdana>
<HR style="WIDTH: 122px; MIN-HEIGHT: 2px" align=left SIZE=2>
<SPAN class=HOEnZb><FONT color=#888888></FONT></SPAN></FONT></DIV><SPAN
class=HOEnZb><FONT color=#888888>
<DIV align=left><FONT color=#c0c0c0
face=Verdana><SPAN>yjunwei2012</SPAN></FONT></DIV>
<DIV><FONT face=Verdana>
<HR>
</FONT></DIV>
<DIV><FONT face=Verdana><STRONG>发件人：</STRONG><A
href="mailto:manchugh@iitk.ac.in"
target=_blank>manchugh@iitk.ac.in</A></FONT></DIV>
<DIV><FONT face=Verdana><STRONG>发送时间：</STRONG><A href="tel:2014-04-23%C2%A005"
target=_blank value="+12014042305">2014-04-23 05</A>:04</FONT></DIV>
<DIV><FONT face=Verdana><STRONG>主题：</STRONG>Re: [Pw_forum] The relax
problem</FONT></DIV>
<DIV><FONT face=Verdana><STRONG>收件人：</STRONG>"PWSCF Forum"<<A
href="mailto:pw_forum@pwscf.org"
target=_blank>pw_forum@pwscf.org</A>></FONT></DIV>
<DIV><FONT face=Verdana><STRONG>抄送：</STRONG></FONT></DIV></FONT></SPAN>
<DIV>
<DIV class=h5>
<DIV><FONT face=Verdana></FONT> </DIV>
<DIV><FONT face=Verdana>
<DIV>Dear JWY </DIV>
<DIV> </DIV>
<DIV>Your output file still has the same number of atoms. There is no problem </DIV>
<DIV>with your system. You can see the missing atoms in the image you sent by </DIV>
<DIV>using "Number of units drawn" option in Modify tab of xcrysden. </DIV>
<DIV> </DIV>
<DIV>Thank you </DIV>
<DIV>Manjusha </DIV>
<DIV>Ph.D student </DIV>
<DIV>IIT Kanpur </DIV>
<DIV>India </DIV>
<DIV> </DIV>
<DIV>> Hello dear QE users, </DIV>
<DIV>> I have used the 'calculation=relax' to calculation a 48 atomes' system, </DIV>
<DIV>> and I compare the structure data(after relax) with the one from input </DIV>
<DIV>> file(before relax),I find that there has a big difference. Then I </DIV>
<DIV>> import the two structures to Xcrysden, the result as the above two </DIV>
<DIV>> pictures show that, I do not understand why and wonder if some problems </DIV>
<DIV>> with symmetry? I am not sure. </DIV>
<DIV>> I look forward to your suggestion! Thank you! </DIV>
<DIV>> </DIV>
<DIV>> Best wishes! </DIV>
<DIV>> JWY </DIV>
<DIV>> </DIV>
<DIV>> 2014-04-22 </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> </DIV>
<DIV>> yjunwei2012_______________________________________________ </DIV>
<DIV>> Pw_forum mailing list </DIV>
<DIV>> <A href="mailto:Pw_forum@pwscf.org"
target=_blank>Pw_forum@pwscf.org</A> </DIV>
<DIV>> <A href="http://pwscf.org/mailman/listinfo/pw_forum"
target=_blank>http://pwscf.org/mailman/listinfo/pw_forum</A> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>_______________________________________________ </DIV>
<DIV>Pw_forum mailing list </DIV>
<DIV><A href="mailto:Pw_forum@pwscf.org"
target=_blank>Pw_forum@pwscf.org</A> </DIV>
<DIV><A href="http://pwscf.org/mailman/listinfo/pw_forum"
target=_blank>http://pwscf.org/mailman/listinfo/pw_forum</A> </DIV></FONT></DIV></DIV></DIV></DIV><BR>_______________________________________________<BR>Pw_forum
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target=_blank>http://pwscf.org/mailman/listinfo/pw_forum</A><BR></BLOCKQUOTE></DIV><BR><BR
clear=all>
<DIV><BR></DIV>-- <BR>
<DIV dir=ltr>_________________________________________<BR>Filipe Camargo
Dalmatti Alves Lima<BR>PhD Student<BR>University of São Paulo, Physics
Institute, Materials Physics Department, Nanomol Group, Brazil.<BR>Phones:
(11) 3091-6881 (USP)<BR>
(11) 97408-2755
(Vivo)<BR></DIV></DIV></FONT></DIV></BODY></HTML>