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<p>Dear Song,</p>
<p><br>
</p>
<p>I'm not really an expert, but I hope this answer help you:</p>
<p>There is no such feature as an autopilot for PW to my knowledge.</p>
<p><br>
</p>
<p>I see three solutions:</p>
<p><br>
</p>
<p>A) You use the ion_temperature = 'reduce-T' (see
<a class="moz-txt-link-freetext" href="https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm899">https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm899</a>). You
can reduce the temperature every <i>nraise</i> steps by <i>delta_t</i>.
(which seems to do what you have in mind)<br>
This will use the velocity rescaling thermostat.<br>
</p>
<p><br>
</p>
<p>B) If you want to use a different thermostat implemented, you can
reset the temperature in an outer loop as in (bash):</p>
<p> for tempw in {1500..300..50}; do <br>
</p>
<p> echo $tempw;</p>
<p> sed -e "s/TEMPW/${tempw}" template.in > md_${tempw}.in</p>
<p> mpirun -np X pw.x <md_${tempw}.in > md_${tempw}.out</p>
<p> done<br>
</p>
<p>Make sure each run restarts properly from the previous (including
positions and velocities).<br>
If you keep the same prefix and outfolder, than
restart_mode='restart' will do what you want. <br>
</p>
<p><br>
</p>
<p>C) If, and only if, you are comfortable coding a bit in Fortan,
and you have quite a complex temperature regime, you can go into
PW/src/dynamics_module.f90</p>
<p>There, you will find a line:<br>
</p>
<p>IF ( control_temp ) CALL apply_thermostat()</p>
<p>For QE6.4.1 this is line 219, for example.</p>
<p>Before this line, you can reset the temperature as a function of
the current MD-step.<br>
</p>
<p>temperature = complicated_function(istep)</p>
<p>I haven't tested this of course.</p>
<p><br>
</p>
<p>Best,</p>
<p><br>
</p>
<p> Leonid Kahle<br>
</p>
<p><br>
</p>
<pre><i>Doctoral Assistant
</i><i>EPFL STI IMX THEOS</i><i>
</i><i>CH-1015 Lausanne (Switzerland)</i></pre>
<div class="moz-cite-prefix">On 6/17/19 4:55 AM, song Kingest wrote:<br>
</div>
<blockquote type="cite"
cite="mid:BY5PR07MB7173454F809F879B50D045E7C6EB0@BY5PR07MB7173.namprd07.prod.outlook.com">
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Dear QE experts,</div>
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<span style="margin:0px">I want to generate metallic glasses
through qe. I am using the md calculation in the pw.x
module. It consists of three processes, calculating 5000
steps in the case of 1500 K, reducing the system temperature
by 500 K every 20 steps, a total of 30,000 steps, and
finally calculating 5000 steps at 300 K.<br>
</span>
<div style="margin:0px">One question is how to link these
three processes. I don't know how to import the 1500 K
calculation results into the cooling process for
calculation. Similarly, the second process to the third
process has similar problems.<br>
</div>
<div style="margin:0px">In the cp.x module, I found the
AUTOPILOT function. This feature allows for temperature
changes during the simulation.<br>
</div>
<div style="margin:0px">
<pre style="font-size:14px; background-color:rgb(255,255,255)">AUTOPILOT
on_step = 31 : dt = 5.0
on_step = 91 : iprint = 100
on_step = 91 : isave = 100
on_step = 191 : ion_dynamics = 'damp'
on_step = 191 : electron_damping = 0.00
on_step = 691 : ion_temperature = 'nose'
on_step = 691 : tempw = 150.0
ENDRULES</pre>
<br>
</div>
<div style="margin:0px">However, the md calculation in the
pw.x module does not have the corresponding function.
Therefore, I would like to ask if you have any solutions?<br>
</div>
<span style="margin:0px">thank you all!<span title="::"
style="margin:0px">😄</span></span></div>
<br>
</div>
<br>
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