[Pw_forum] Temperature continuously going down in cp.x run

[Somesh Kumar Bhattacharya]

Dear Vega,

The CP program prints different energy in the output file *.evp. In this
file the eighth column is the constant of motion which should remain a
constant. Plot this eighth column vs the timesteps and see what fluctuations
are you getting in the plot.

This is I guess what Stefano asked you.

Regards,

Somesh

On Fri, Nov 27, 2009 at 12:42 PM, vega lew <quantumdft at gmail.com> wrote:

> Dear sir,
>
> Did you ask whether the (etot+ekinc) conserve during the dynamic process?
>
> I sum the corresponding columns. I found it is not changing very much.
>
> For example, the (ekinc+ etot) is -4369.40879 (-4369.44669+0.0379) at 2200
> step.
> Then it changes to -4369.41514 (-4369.45479+0.03965) at 2300 step.
> And it sometimes goes a little up and sometimes a little down. But the
> value is in range of
> -4369.41 and -4369.45.
>
> thank you for reading.
>
> vega
>
>
>
> On Fri, Nov 27, 2009 at 2:02 AM, Stefano de Gironcoli <degironc at sissa.it>wrote:
>
>> is the total  (kinetic + potential)  energy conserved ?
>> stefano
>>
>> vega lew wrote:
>> > dear all,
>> >
>> > I want to calculate certain heterogeneous reaction on a solid surface.
>> > First input the initial structure from previous pw.x relaxations.
>> > Second I fixed ions and let electron damping calculation run;
>> > Then un-fixed the ions and let both electron  and ions damping
>> > calculations run.
>> > Third I gave a random motion to the atoms in the system with
>> > amprp(1)~(3) = 0.01
>> > and then repeated second step to bring the system to the ground state.
>> > Fourth I added temperature (300K) to the system, using verlet schedule.
>> >
>> > But the temperature continuously going down, from 1000K to 150K during
>> > the fisrt 3000 steps.
>> > I think there might be something wrong with my cp.x calcuation.
>> > Do you think the amprp(1)~(3) = 0.01 of random motion is too small?
>> >
>> > Here is the input of my dynamics process,
>> >  &CONTROL
>> >
>> >                        title = 'CP'
>> > ,
>> >                  calculation = 'cp'
>> > ,
>> >                 restart_mode = 'restart'
>> > ,
>> >                       outdir = '/disk5/nanjing/vega/cp/300/' ,
>> >                       wfcdir = '/tmp/'
>> > ,
>> >                   pseudo_dir =
>> > '/home/software/nanjing/vega/espresso-4.0.1/pseudo/' ,
>> >                       prefix = 'cp_molecular' ,
>> >                        nstep = 99999 ,
>> >                           dt = 10,
>> >                       iprint = 5,
>> >                        isave =
>> > 150,
>> >  /
>> >
>> >  &SYSTEM
>> >
>> >                        ibrav =
>> > 8,
>> >                    celldm(1) =24.8624,
>> >                    celldm(2) = 0.8520,
>> >                    celldm(3) = 1.6964,
>> >                          nat =
>> > 147,
>> >                         ntyp = 3,
>> >                         nr1b = 20,
>> >                         nr2b = 20,
>> >                         nr3b = 20,
>> >                         nbnd =
>> > 630,
>> >                    ecutwfc   =   30,
>> >                    ecutrho   =  300,
>> >  /
>> >
>> >
>> >  &ELECTRONS
>> >            electron_dynamics = 'verlet',
>> >  /
>> >
>> >  &IONS
>> >
>> >                 ion_dynamics = 'verlet'
>> >              ion_temperature = 'nose',
>> >                        tempw = 300,
>> >  /
>> > ..................
>> > ..................
>> >
>> > best wishes,
>> >
>> > vega
>> >
>> > --
>> >
>> ==================================================================================
>> > Vega Lew ( weijia liu)
>> > Graduate student
>> > State Key Laboratory of Materials-oriented Chemical Engineering
>> > College of Chemistry and Chemical Engineering
>> > Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
>> >
>> ******************************************************************************************************************
>> > Email: vegalew at gmail.com <mailto:vegalew at gmail.com>
>> > Office: Room A705, Technical Innovation Building, Xinmofan Road 5#,
>> > Nanjing, Jiangsu, China
>> >
>> ******************************************************************************************************************
>> >
>> > ------------------------------------------------------------------------
>> >
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>> >
>>
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>
>
>
> --
>
> ==================================================================================
> Vega Lew ( weijia liu)
> Graduate student
> State Key Laboratory of Materials-oriented Chemical Engineering
> College of Chemistry and Chemical Engineering
> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
>
> ******************************************************************************************************************
> Email: vegalew at gmail.com
> Office: Room A705, Technical Innovation Building, Xinmofan Road 5#,
> Nanjing, Jiangsu, China
> ******************************************************************************************************************
>
>
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-- 
Somesh Kr. Bhattacharya
Post Doctoral Fellow
Room No. 263,
Leonardo Building,
The Abdus Salam International Centre for Theoretical Physics
Strada Costiera, 11
I-34014 Trieste
Italy
Phone: +39-040-2240399
http://portal.ictp.it/cmsp/members/postdoctoral-fellows/somesh-kumar-bhattacharya/
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