Dissociation energies of silicon clusters: A depth gauge for the global minimum on the potential energy surface

We have modeled the dissociation of Si-n neutrals and cations in the n less than or equal to 26 range. The fragmentation pathways up to n = 26 and dissociation energies up to n = 20 have been calculated assuming a statistical decomposition process. The results for the cations are in good agreement with the measurements. This indicates that our search of configuration space for the silicon clusters in this size range has indeed found the global minima-a family of "stacked Si-9 tricapped trigonal prisms." This is the first time that dissociation energies have been used to test the results of a global optimization. [S0031-9007(98)07726-6].