[gmx-users] Ion self-interaction energy?

[Justin Lemkul]

On 8/3/15 10:21 PM, Leandro Bortot wrote:
> Dear users,
>
>       I simulated system consisting of a protein complexing a single calcium
> cation. I used explicit water and ions (Na+ and Cl-) in the solution to
> neutralize the charge and mimic ionic strenght effects.
>
>       I was investigating some interactions and found that if I select the
> energy term "Coul-SR:CA-CA" with g_energy I got a constant value of
> -979.327 kJ/mol. I checked and the "CA" group indeed correspond to the
> single Ca2+ in the simulation.
>      What is the meaning of this "self-interaction" energy? How should I
> interpret it?
>

As buggy or incorrect.  An atom should have no interaction with itself.

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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