AbstractA path‐integral Monte Carlo (PIMC) method has been used to investigate the dynamics of the Ar dimer and trimer with temperature. Energy and radial distributions are compared with estimates obtained from alternative approaches based on the calculation of the discrete and continuum rovibrational spectra of the two systems. The analysis of the Ar2 case reveals that the system only evolves between the equilibrium configuration and the breaking of the ArAr bond. This feature thus differs from the situation observed for the trimer in a previous study where the existence of a collinear isomer between the equilateral arrangement and the predissociative ArAr2 structure was manifested. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011