Re: sodium ion in water

From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Thu Aug 11 2011 - 00:36:08 CDT

On Thu, Aug 11, 2011 at 1:17 AM, divya nayar <divya.alchemist_at_gmail.com> wrote:
> Hi,
> I want to simulate one sodium ion in 255 molecules of water (SPC/E).  The
> ion will be considered as charged Lennard Jones sphere and I am using
> Dang-Smith paramters for the sodium ion. I would like to ask, what should I
> do to define a compensating electric field for my system because my system
> is not neutral?

you don't need to do anything. the compensating charge
will follow automatically from using long-range electrostatic
with PME.

>
> Can anyone suggest on the above or some reference ?

any textbook on MD that explains ewald summation and
PME should be a sufficient reference. the compensating
charge is a side effect of ignoring the non-periodic term
at k=0.

cheers,
    axel.

> Thanks
> Divya
>

-- 
Dr. Axel Kohlmeyer
akohlmey_at_gmail.com  http://goo.gl/1wk0
Institute for Computational Molecular Science
Temple University, Philadelphia PA, USA.

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