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

Somesh Kumar Bhattacharya somesh.kb at gmail.com
Fri Nov 27 13:33:39 CET 2009


Dear Vega,

something is wrong in your simulation. I don't know exactly what. The
constant of motion is changing by 0.01 hartree  which is quite significant.

Regards,

Somesh

On Fri, Nov 27, 2009 at 1:26 PM, vega lew <quantumdft at gmail.com> wrote:

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


-- 
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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