Applications of combined diatomics-in-molecules/ab initio approaches to Ne n + , Ar n * , Ar n Cl 2 , and Ar n NO clusters are discussed. Simple perturbative models within these procedures are suggested to interpret the predicted cluster structures, obtained using a basin-hopping global optimization algorithm. The topological peculiarities of the Ar-NO potential are analyzed in terms of the perturbation of the Ar-N and Ar-O interactions within the complex. The correlation between the solvation of a chromophore species in the cluster and the relative strength of the solvent-solvent and chromophore-solvent interactions is also analyzed.