The intermolecular potential between Ar atom and ICl fixed at its equilibrium is determined by CCSD(T) calculations. We used effective-core potentials for iodine, augmented correlation consistent basis sets (aug-ce-pVnZ, n = T,Q) for Cl and Ar atoms with an additional set of bond functions. The global potential minimum corresponds to the linear Ar-I-Cl structure with well-depth D-e = 328.1 cm(-1), r((ArI)-I-. . .) = 3.555 Angstrom and k(s) = 3.45 N m(-1), in accord with the one determined by the experiment with r((ArI)-I-. . .) = 3.576 Angstrom and k(s) = 3.20 N m(-1). Bound state calculations are carried out for J = 0 and 1 rotational states. Accordingly, the lowest level corresponds to linear Ar-I-Cl isomers, while stable isomers are also found for T-shaped and antilinear species. (C) 2003 Elsevier Science B.V. All rights reserved.