THE ARCLF VAN-DER-WAALS COMPLEX AS AN EXAMPLE OF HOW ATOMS INSIDE A MOLECULE INTERACT WITH THOSE OUTSIDE

The evolution of the ground state Ar-ClF potential energy surface incl uding interactions of different order between the Cl and F atoms is co nsidered by means of a simple model interpolating results of high-leve l ab initio calculations and directly transferable to ArnClF clusters and solids. The anisotropy of the potential is interpreted in terms of separate atom-atom contributions and exhibits a strong variation when 3-body effects are included. Effective interactions of Cl and F with Ar are obtained explicitly and found to be distorted significantly by strong intramolecular forces.