use the empirical correction term of DFT-D3 in the classical MD

[Marco]

Hello,

In addition to my previous post. Are you trying to add a functional term to 
the MM force field potential which is similar to the DFT-D3 expression? If 
so, would the GENPOT 
(http://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/MM/FORCEFIELD/NONBONDED/GENPOT.html) 
functionality serve your purpose. With GENPOT you can specify a generic 
potential type. I have not used GENPOT myself yet but I would be interested 
in any results obtained with GENPOT.

Regards,
Marco

On Friday, May 23, 2014 11:37:51 PM UTC-4, Marco wrote:
>
> Dear JianBiao,
>
> Yeah that sounds like a reasonable approach. You are using QM data derived 
> from DFT-D3 calculations to parameterize a force field of a certain 
> functional form (presumably employing the Tang-Toennies damping function as 
> the non-bonded component in addition to bond/angle/dihedral etc. terms). 
> Your QM data from the DFT-D3 calculations account for dispersion effects 
> and this should transfer over into your force field parameterization in the 
> case of a good fit. As you know since you work with parameterization, one 
> measure of a good fit is whether your parameterized force field 
> calculations reproduce your QM reference data set and certain properties of 
> your system. Anthony J. Stone has published a lot of good work in this 
> field. 
> (http://www-stone.ch.cam.ac.uk/personal/bibliography.html)
>
> What do you mean by add the DFT-D3 to the classical MD parts?
>
> Best regards,
> Marco
>
> On Friday, May 23, 2014 9:38:32 PM UTC-4, JianBiao wrote:
>>
>> Dear Marco,
>>     Thank you for your reply. I am sorry I didn't say my question 
>> clearly. During the force-matching process, one can use the forces 
>> calculated from the PBE-AIMD as the references, then one can parameterize 
>> some parameters in the force field such as V(A, B, .. C6=0, C8=0). Because 
>> PBE fails to describe the dispersion effects, one cannot get the C6 and C8 
>> from the force-matching. Then during the MD simulation, one can use the 
>> Grimme's damped empirical correction terms to calculate the dispersion 
>> parts. So I think this method is reasonable. Could you please give some 
>> comments? Could someone please help to add the DFT-D3 to the classical MD 
>> parts?
>>
>> Best, JianBiao
>>    
>>
>>
>>
>>
>> 在 2014年5月24日星期六UTC+8上午7时45分00秒，Marco写道：
>>>
>>> Hello,
>>>
>>> DFT and classical MD are two very different model chemistry's. The 
>>> parameterizations for BMHFTD (if and when available) and DFT-D3 are 
>>> completely different. It would be unsound to transfer Grimme's damped 
>>> empirical correction terms into a classical MD force field in such a 
>>> straightforward manner. At least I have not seen it done in the literature. 
>>>
>>> Regards,
>>> Marco
>>>
>>> On Friday, May 23, 2014 8:23:10 AM UTC-4, JianBiao wrote:
>>>>
>>>> Dear CP2K developers,
>>>>     Is it possible to use DFT-D3 to calculate the dispersion energies 
>>>> during the classical MD simulations? Because the dispersion term in  
>>>> CP2K_INPUT <http://manual.cp2k.org/trunk/CP2K_INPUT.html> / FORCE_EVAL<http://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL.html>
>>>>  / MM <http://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/MM.html> / 
>>>> FORCEFIELD<http://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/MM/FORCEFIELD.html>
>>>>  / NONBONDED<http://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/MM/FORCEFIELD/NONBONDED.html>
>>>> /
>>>> BMHFTD<http://manual.cp2k.org/trunk/index.html#CP2K_INPUT/FORCE_EVAL/MM/FORCEFIELD/NONBONDED/BMHFTD.html>
>>>>  is similar to Grimme's damped empirical correction, one can use the 
>>>> dft-d3 to calculate the dispersion energy and corresponding forces. Could 
>>>> you please give some suggestions? 
>>>>
>>>> Best wishes
>>>> JianBiao
>>>>
>>>
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