[gmx-users] How to calculate the number of salt ions?

[David]

On Wed, 2004-03-24 at 04:56, Yinghong wrote:
> Hi, all:
> 
> To make the simulation under a more natural environment, maybe, some
> NaCl molecules are needed to add into water solvent.
> 
> My question is whether this step is necessary? and how many Na and Cl
> ion pairs should be added?
> 
> This problem is probably a little silly, but I do wanna know about the
> answer!

No it is a serious problem. Physiological salt concentration is roughly
150 mM, so 1 NaCl for every 300-350 water molecules.

> 
> Your help will be greatly appreciated!
> 
>  
> 
> Regards
> 
> Xie YH
> 
>  
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assist. 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://xray.bmc.uu.se/~spoel
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