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

vega lew quantumdft at gmail.com
Fri Nov 27 13:26:03 CET 2009


Dear friend,

thank you for you information.
I attach the file in the list. In the file, I find the 8th column is not
remain the same.

thank you again.

vega

On Fri, Nov 27, 2009 at 4:04 AM, Somesh Kumar Bhattacharya <
somesh.kb at gmail.com> wrote:

> 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
>>> >
>>> ******************************************************************************************************************
>>> >
>>> >
>>> ------------------------------------------------------------------------
>>> >
>>> > _______________________________________________
>>> > Pw_forum mailing list
>>> > Pw_forum at pwscf.org
>>> > http://www.democritos.it/mailman/listinfo/pw_forum
>>> >
>>>
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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
>> ******************************************************************************************************************
>>
>>
>> _______________________________________________
>> Pw_forum mailing list
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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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>
>


-- 
==================================================================================
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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