<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 class="" style="white-space:pre"> </span>REAL</div><div>Default:<span class="" 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 class="" style="white-space:pre"> </span>REAL</div>
<div>Default:<span class="" 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="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><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" marginheight="0" marginwidth="0">
<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="min-height:2px;WIDTH:122px" 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" value="+12014042305" target="_blank">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>
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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>
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