Small germanium sulfide clusters: mass spectrometry and density functional calculations.

Germanium sulfide clusters were generated by laser ablation of a solid sample. The resulting molecules were analyzed in a time-of-flight mass spectrometer. In addition to atomic germanium and diatomic sulfur, the spectra exhibited evidence for the existence of clusters containing up to four germanium atoms. Unlike the more commonly observed log-normal distribution of clusters as a function of cluster size, the abundance and even the appearance of a particular cluster appeared to depend upon the likelihood of forming the cluster from a smaller molecule. The potential structures of the observed clusters were computationally investigated using a density-functional approach.