Intermolecular minimitation

[qftramos "-at-" usc.es (Antonio Fernandez Ramos)]

 I have a dimer intermolecular potential with several parameters; the
 variables are the distances between atoms. I want to optimize the
 intermolecular coordinates but keeping the intramolecular coordinates
 fixed, as well as two intermolecular coordinates, one angle and one
 distance.
 Is there any program available which will allow me to introduce the
 potential depending on the distances and the restrictions, and which
 will optimize the rest of the coordinates, and be easy to use?
 					Thanks.