Analogy of silicon clusters with deltahedral boranes: how far can it go? Reexamining the structure of Sin and Sin 2-, n=5-13 clusters.

Silicon clusters of 5 up to 13 atoms, Si(n), n=5-13, and their dianions are studied in the light of an anticipated analogy with the corresponding isoelectronic boranes suggested recently by Zdetsis [J. Chem. Phys. 127, 014314 (2007)]. It is demonstrated that this analogy is a fruitful and powerful concept which allows the straightforward determination of the structures of silicon clusters, based on the structure of corresponding closo-boranes, meeting the requirements of well known structural rules. All lowest-lying structures of Si(n), n=5-13 clusters, have been obtained through a systematic way on the basis of this analogy. For magic clusters, such as Si(6) and Si(10), characterized by special stability, the analogy to boranes seems to be much stronger.