simulated annealing using CP2K

[Geng Sun]

Hello CP2K users 

      Could anyone give me some hints that how to do fix cell simulated annealing to find the stable structures in CP2K ?

Thanks in advance !

[Samuel Andermatt]

I don't think you can change the temperature over the course of a simulation, you will have to do multiple runs, one for each temperature. Fixed cell you have by choosing the NVT ensamble.

[Matt W]

There is an ANNEALING variable in the MD section. My understanding is that at each step velocities would be rescaled by this factor (I've never used it).

Matt

[Marcella Iannuzzi]

Yes ANNEALING works like this. Use a value smaller than 1 to decrease and larger than 1 to increase the temperature.

Be careful with the choice of the value, because the scaling factor is applied at each MD step to all velocities.

regards

Marcella

[janos...@gmail.com]

Dear Geng,

It can be done by using the EXT_RESTART option and some simple input files.

template: simple input file with EXT_RESTART from projectname-1.restart, restarting everything, and annealing parameter:

ANNEALING ${PAR}

Then, you can also use the SET and INCLUDE commands in three different inputs:

heating.inp:

@SET PAR 1.000001 #check the number for your needs

@INCLUDE ./template

const.inp

@SET PAR 1.000000

@INCLUDE ./template

cooling.inp:

@SET PAR 0.999999 #check the number for your needs

@INCLUDE ./template

then you simply write a script:

#! /usr/bin/bash

for i in {1..99999}; do  #again adjust to your needs

  cp2k.popt const.inp >>out

  cp2k.popt heating.inp >>out

  cp2k.popt const.inp >>out

  cp2k.popt cooling.inp >>out

done

You can set different simulation times by the SET command as well...

If you want, you can set different project names for different temperatures as well, so you can have the different temperature structures in different xyz files. And it is also a good idea to set the temperature by @SET for the input files.

HTH,

Janos

[Geng Sun]

Janos,

    Thanks ! that's very helpful. I will give it a try.

Geng Sun

[jing...@outlook.com]

Hi, Janos. Recently, I am learning simulated annealing to search the global minimum of small molecule. I saw your nice suggestion, but I have some questions,

For annealing, how to set the temperature? I tested my input file, when I use the keywords temperature and annealing, the error implied thermostat is needed. 

But thermostat and annealing are against, so I wonder how to set the temperature? And  in every input files(heating and cooling), should I do NVE simulations or

just do the optimization? 

      Thanks.

       

       Jing

在 2015年7月27日星期一 UTC-7下午5:53:32，Geng Sun写道：

[jing...@outlook.com]

Hi, Geng. How do you use the simulated annealing? Could you send me some input files. THANKS!

      Jing

在 2015年7月23日星期四 UTC-7上午12:57:38，Janos...@googlemail.com写道：