The problem of constructing reaction paths for conformational changes in noble gas clusters, which are formed by weak dispersion forces has been discussed. The potential energy surface describing these systems are extremely rugged and contains a large number of minima and saddle points within a narrow energy range. So it is not beyond expectation that there must exist a number of paths describing conformational changes in these systems in the given energy range and these bunch of paths provide a better description of possible conformational changes as opposed to the conventional single minimum energy path. To study this issue we have taken up the Ar18 cluster as a typical example and the entire formulation is done with the use of the stochastic search strategy of simulated annealing. The quantitative results clearly show the existence of a large number of minima and transition states and also a multitude of probable transforming paths between stable geometries. © 2017, Springer International Publishing AG.