Remarkable periodicity ofGenpions (n/p≲25, 1≤p≤4) formed by the liquid-metal ion-source technique

We present the mass spectrum of ${\mathrm{Ge}}_{\mathrm{n}}$ ${\mathrm{}}^{\mathrm{p}}$ (1≤p≤4) ions formed by the liquid-metal ion-source (LMIS) technique. We observe that the ${\mathrm{Ge}}_{\mathrm{n}}$ ${\mathrm{}}^{3+}$ ions present, as do the ${\mathrm{Sn}}_{\mathrm{n}}$ ${\mathrm{}}^{3+}$ ions, a remarkable modulo-6 periodicity. This phenomenon is interpreted as due to stability maxima which appear when the number of atoms is such that it is possible to form an integer number of eight-atom rings. We propose possible geometries for the clusters with n=6 to n∼80.