Dear Song,
I'm not really an expert, but I hope this answer help you:
There is no such feature as an autopilot for PW to my knowledge.
I see three solutions:
A) You use the ion_temperature = 'reduce-T' (see
https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm899). You can
reduce the temperature every /nraise/ steps by /delta_t/. (which seems
to do what you have in mind)
This will use the velocity rescaling thermostat.
B) If you want to use a different thermostat implemented, you can reset
the temperature in an outer loop as in (bash):
for tempw in {1500..300..50}; do
echo $tempw;
sed -e "s/TEMPW/${tempw}" template.in > md_${tempw}.in
mpirun -np X pw.x <md_${tempw}.in > md_${tempw}.out
done
Make sure each run restarts properly from the previous (including
positions and velocities).
If you keep the same prefix and outfolder, than restart_mode='restart'
will do what you want.
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
There, you will find a line:
IF ( control_temp ) CALL apply_thermostat()
For QE6.4.1 this is line 219, for example.
Before this line, you can reset the temperature as a function of the
current MD-step.
temperature = complicated_function(istep)
I haven't tested this of course.
Best,
Leonid Kahle
/Doctoral Assistant //EPFL STI IMX THEOS////CH-1015 Lausanne (Switzerland)/
On 6/17/19 4:55 AM, song Kingest wrote:
Dear QE experts,
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.
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.
In the cp.x module, I found the AUTOPILOT function. This feature
allows for temperature changes during the simulation.
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
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?
thank you all!😄
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_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
