[gmx-users] dispersion corrections in an anisotropic system

[Justin A. Lemkul]

Zuzana Benkova wrote:
> Dear GROMACS users,
> 
> my system is composed of a repulsive surface with chains grafted on it 
> and other free chains above this immobilized system. I am hesitating 
> whether to use dispersion corrections for the pressure and energy or 
> not. Without these corrections the repulsion of the grafting surface 
> increases which is understandable. This is however, no a problem because 
> under such conditions I can decrease this repulsion by the manipulation 
> of LJ parameters. However, I think that the dispersion corrections are 
> necessary for representation of the interactions between the bulk free 
> chains wetting the anchored chains. Though in the melt they should be 
> screened, but I am varying the densities of the system and not all cases 
> represent melt situation. I have checked the mailing list but I have not 
> found satisfactory answer. I have not found some way how to treat long 
> range interactions of heterogeneous system.
> 
> My next question is very trivial, but I can not find in Manual and other 
> sources meaning of AllEnerPres.
> 

I can't comment on the first question, but in this case note that "AllEnerPres" 
is not a valid option.  The three options for DispCorr are "no," "Ener," and 
"EnerPres."  These indicate the terms that dispersion correction affects, either 
nothing, energy only, or both energy and pressure.

-Justin

> Thank you for your answer in advance.
> 
> Greetings
> Zuzana
> 

-- 
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Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
MILES-IGERT Trainee
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

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