Subject: ion-water three-body potential

From: Hannes Loeffler <[email-masked]>
Date: 02 Oct 2000 09:16:38 +0200

Dear CCLers,

we would like to improve our MD simulations of ions in aqueous solution with
a three-body potential between the ion and water.  Currently we use the
flexible CF2 water model including a special intra-molecular potential.  The
ion-water interactions are calculated ab initio at an appropriate level.

Now we would like to know if we can get away with a simple three-body potential
by sampling at various O-ion-O distances and angles (the water geometry
remains rigid).  However, the question is how the forces of the atoms of the
water molecule should be calculated.  Some rigid water models from the
literature compute forces for just the ion and the oxygens.

Is it possible to adopt such a simple model also to a flexible water molecule?
Is it valid to assume that the hydrogens will adjust properly under the
influence of the two-body and intra-molecular forces only?

We would be grateful for pointers to the literature or any other hint.

Hannes Loeffler.

-- 
Hannes Loeffler, Tel. +43-512-507-5166
Institute for General, Inorganic and Theoretical Chemistry
University of Innsbruck/Austria