The mass spectra of FA water clusters obtained with a photon energy of 12.5 eV is shown in Figure . A series of protonated FA clusters with up to 7 FA molecules are observed, along with clusters of these protonated FA moieties and water molecules (series indicated in figure This distribution occurs due to the high stability of certain cluster sizes. This is true for the following cluster sizes: As the water content of their mixtures was increased, the discontinuity (magic numbers) disappeared leading to smooth distributions. Hence it is clear that one needs to work within water-poor regimes to be able to generate these magic number distributions. In the next section, we will describe theoretical calculations undertaken to explain the stability of these cyclic clusters.