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<p>Hi Sridhar, <br>
</p>
<p>Thank you for your reply. I followed your instructions on only changing the task to both 'relax' and 'vc-relax' in my input file. However, I got the following error for both of them:
<br>
</p>
<p><font color="#FF0000">task # 0<br>
from read_namelists : error # 1<br>
reading namelist ions</font><br>
</p>
<p><br>
</p>
<p>Following a tutorial on the internet and according to the above error , at first, I only added the namelist &ions and got an output (very small output). So Again I added other parameters in the &control namelist based on the same tutorial (without knowing
what they are) and got another output. I was wondering if you would kindly take a look at my final input file and tell me what those parameters that I added are.
<br>
</p>
<p><br>
</p>
<p>Here is my input file: <br>
</p>
<p><br>
</p>
<p><font color="#006fc9">&control<br>
calculation='relax',<br>
</p>
<p> nstep= 50, <font color="#FF0000"><========== I added this</font>
<br>
</p>
<p> etot_conv_thr= 1.d-4, <font color="#006fc9"><font color="#FF0000"><========== I added this</font> </font><br>
</p>
<p> forc_conv_thr= 2.d-3, <font color="#006fc9"><font color="#FF0000"><========== I added this</font> </font><br>
</p>
restart_mode='from_scratch',<br>
prefix='si',<br>
pseudo_dir = '../pseudo',<br>
/<br>
<br>
&system<br>
ibrav= 2,<br>
celldm(1) =10.187,<br>
nat= 2,<br>
ntyp= 1,<br>
ecutwfc =16,<br>
/<br>
<br>
&electrons<br>
conv_thr = 1.0d-10,<br>
/<br>
<br>
&ions<br>
<p> ion_dynamics = 'bfgs', <font color="#006fc9">
<font color="#FF0000"><========== I added this</font></font><br>
</p>
<p> pot_extrapolation= 'second_order', <font color="#006fc9"><font color="#FF0000"><========== I added this</font> </font><br>
</p>
<p> wfc_extrapolation= 'second_order', <font color="#006fc9"><font color="#FF0000"><========== I added this</font> </font><br>
</p>
<p> upscale = 100, <font color="#006fc9">
<font color="#FF0000"><========== I added this</font></font><br>
</p>
/<br>
ATOMIC_SPECIES<br>
Si 28.086 Si.pz-vbc.UPF<br>
<br>
ATOMIC_POSITIONS<br>
Si 0.00 0.00 0.00<br>
Si 0.25 0.25 0.25<br>
<br>
K_POINTS AUTOMATIC<br>
4 4 4 1 1 1</font><br>
<br>
<p></p>
<p><br>
</p>
<p>Thank you,<br>
</p>
<p><br>
</p>
<div id="Signature">
<div id="divtagdefaultwrapper" style="font-size:12pt; color:#000000; background-color:#FFFFFF; font-family:Calibri,Arial,Helvetica,sans-serif">
<p>Amir M. Mofrad<span> <br>
</span></p>
<p>University of Missouri<br>
</p>
</div>
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<br>
<br>
<div style="color: rgb(0, 0, 0);">
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> pw_forum-bounces@pwscf.org <pw_forum-bounces@pwscf.org> on behalf of Sridhar Sadasivam <sridhu88@gmail.com><br>
<b>Sent:</b> Wednesday, October 21, 2015 6:51 PM<br>
<b>To:</b> PWSCF Forum<br>
<b>Subject:</b> Re: [Pw_forum] Geometry (Structural) Optimization</font>
<div> </div>
</div>
<div>
<div dir="ltr">Hi Amir,
<div>The calculation for geometry optimization does not require data from any previous scf runs - It is a separate calculation. You need to use the same pw.x program that you use for scf. But just change the calculation parameter in &control namelist to 'relax'
or 'vc-relax'. Apart from that, your input file is quite similar to that for scf.</div>
<div>Sridhar</div>
<div>Purdue University</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Oct 21, 2015 at 7:51 PM, Mofrad, Amir Mehdi (MU-Student)
<span dir="ltr"><<a href="mailto:amzf5@mail.missouri.edu" target="_blank">amzf5@mail.missouri.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex; border-left:1px #ccc solid; padding-left:1ex">
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<p>Hi all, </p>
<p><br>
</p>
<p> I have done an SCF calculation on a silicon unit cell and I want to do a structural (geometry) optimization next. The documentation for this purpose was not that helpful and I have a couple of questions, for instance should I use the data generated from
the scf calculation or should I define a thoroughly different input file for this calculation? What is the command to do so? Is it the same as pw.x or something else? Any help would be appreciated. </p>
<p><br>
</p>
<p>Thank you,</p>
<p><br>
</p>
<p>Amir</p>
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<p><br>
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