CCL: intermolecular potential

[Naoko Akiya <nakiya (+ at +) engin.umich.edu>]

 Hello,
 I have a very basic question -- please bear with me.  I am still trying to
 learn the basics, and unfortunately, there is no one around me who can
 answer this question.
 I plan to do a simulation of a solution, with one solute molecule
 surrounded by solvent molecules.  Before I do the simulation, I need to
 obtain parameters for the intermolecular and intramolecular potential
 models.
 I plan to use the intramolecular potential models available in the
 literature for both the solute and the solvent.  For the intermolecular
 potential, I will just use the Lennard-Jones and electrostatic interaction
 terms, but I still need to obtain the parameters.
 I would like to obtain those parameters by fitting the ab initio
 interaction energies to this intermolecular potential.  This is where I
 have a question (finally).  When I calculate the interaction energies by
 ab initio methods, should I keep the geometries of the solute and the
 solvent molecules fixed to the equilibrium geometries as specified by the
 intramolecular potential models that I chose?  I am inclined to do so, but
 I wanted to get the opinions of the experts...
 Thank you very much for your patience.
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   Naoko Akiya                        nakiya (+ at +) engin.umich.edu
   University of Michigan
   Dept. of Chemical Engineering      phone (734) 764-7121
   Ann Arbor, MI 48109-2136	     fax   (734) 763-0459
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