Re: [ESPResSo-users] Fwd: Re: conservative paramerters in DPD simulation

[Christoph Junghans]

2012/12/10 Ulf Schiller <address@hidden>:
> -------- Original Message --------
> Subject: Re: [ESPResSo-users] conservative paramerters in DPD simulation
> Date: Mon, 10 Dec 2012 17:02:25 +0100
> From: Ulf Schiller <address@hidden>
> Organization: Forschungszentrum Juelich, ICS-2
> To: guozhicheng222 <address@hidden>
>
>
> On 12/10/2012 04:47 PM, guozhicheng222 wrote:
>>
>> Our simulation is a polymer binder explosive system contained 880 TATB
>> molecules (typed 0) and 120 F_2311 polymers (typed 1). We want to use
>>
>> the DPD methods to investigate the effect of temperature change after
>> impact. The conservative potential, to depict the interactions between
>> beads 0 and 1 and predict the thermodynamics of system, can be described
>> by lennard-jones that contained 6 parameters (ε, σ, r_cut , c_shift and
>> r_off , as showed in ESPresSo user's guide). Therefore, to construct our
>>
>> simulation model, we have to choose the correct parameters of
>> lennard-jones potential. Our question is that how to determine the 6
>> parameters and make sure that they are suitable to describe the
>> interactions between beads 0 and 1.
>
>
> Zhicheng,
>
> I don't know the definite answer to that question, unfortunately. Unless
> anybody on this mailing list has incidentally come across your system,
> which is unlikely, you will have to check the literature on
> coarse-grained models for your specific molecules.
Just one addition to what Ulf said: There are DPD models for TATB around:
<https://e-reports-ext.llnl.gov/pdf/244074.pdf>
Why don't you just use the hat interaction (Stefan and me mentioned
that before) with their parameters.

Christoph
>
> Another thing is to note that DPD typically generates (equilibrium)
> thermodynamics of the NVT ensemble. Although there have been efforts to
> implement energy conservation in DPD and SPH, I am not quite sure how
> accurate temperature changes and heat transport can be captured. Be sure
> to check your results carefully.
>
> Cheers,
> Ulf
>
> --
> Dr. Ulf D. Schiller                        Building 04.16, Room 3006
> Institute of Complex Systems (ICS-2)       Phone:   +49 2461 61-6144
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>
>
>
>



--
Christoph Junghans
Web: http://www.compphys.de