Formation of planar magic Ag nanostructures

Nanometer-sized silver-based clusters have been identified in experiments, as a potential material for planar magic clusters. The density functional optimization of geometrical structures and, correspondingly, binding energy enable the formation of these magic Ag nanoclusters as well as their relative stability to be examined. Calculations show that the evolution of the sequence of planar magic Ag clusters is strongly related to their electronic structures. Only those clusters that exhibit a high degeneracy of electronic states, a large energy gap near the Fermi level, and a symmetric charge density distribution are favorable structures. The substrate also plays an important role in the formation of geometrically optimized structures of magic Ag clusters. With further analysis of their intrinsic electronic properties and extrinsic extra energy gain with substrate consideration, the mechanism of formation and the magic number sequence for planar Ag nanoclusters can be obtained.