[gmx-users] A simple question about reaction-field

[David van der Spoel]

Alexandre Suman de Araujo wrote:
> I´m performing a simulation of an ion in water (TIP3P) using reaction
> field. I define energy_grps = ion sol in my .mdp file.
> 
> When I use rlist = rcoulomb, no LR terms appear in g_energy list.
> When I use rlist < rcoulomb, these LR terms appear.
> 
> So, the LR terms obtained using reaction field is the contribution of
> implicit solvent between rlist and rcoulomb or the contribution of
> implicit solvent beyond rcloumb, as is said in GMX manual and other
> reference texts?
> 
> Thanks
> 
No, the LR energy is still the directly computed energy between the R*.

The reaction field effect is implicit in the Coulomb potential, except 
when you have larger molecules and an exclusion correction term is added.

-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://folding.bmc.uu.se
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