Structural features of silicon clusters SinSin (n=40–57,60n=40–57,60)

The structural transition in inner portions of medium-sized silicon clusters has been a puzzle over a decade. By performing extensive search of the “compressing-liquid-silicon” strategy we proposed together with the “stuffing-fullerene” approach, the low-lying structures of SinSin (n=40–57,60n=40–57,60) are achieved. We reveal that the surfaces of these low-lying isomers are endohedral silicon fullerenelike cages, and the inner portions evolve from loose patterns to aggregate structures as the cluster size increases. These findings not only imply that the stuffed-cage structures are the preferred growth pattern for n=40–57,60n=40–57,60 still, but also clue that before becoming a bulk pattern, the inner portions of clusters undergo transition states.