Benzene-containing molecular clusters are attractive subjects of research because they model the interaction of aromatic -systems. Proper description of the - interactions between the cluster forming monomers of aromatic molecules is essential for understanding the nature of diverse phenomena such as: the tertiary structure of proteins; the porphyrin aggregation; the packing of aromatic molecules in crystals; the vertical base- base interaction in DNA leading to a double helical structure; and the intercalation of certain drugs into DNA. The dimers and higher clusters of aromatic hydrocarbons generated by supersonic jet expansion are ideal systems for a detailed study of the intermolecular potentials because the formation of these species is governed by intermolecular interactions. Thus, the geometrical structures and binding energies of the van der Waals molecules reveal the nature of the forces between molecules and provide an understanding of the clusters properties.