Site- and Structure-Dependent Cohesive Energy in Several Ag Clusters

The cohesive energy of Ag clusters at any site x with the magic number N [ E c x ( N )] is determined through calculating the vacancy formation energy E v x ( N ) using density functional theory and theoretical modeling. It is found that E c x ( N ) is quite distinct at different surface and interior atomic sites within the same cluster. E c x ( N ) is also structure dependent. E c x ( N ) values of the core atoms with an icosahedron structure are much larger than the corresponding bulk value E c (∞) due to the pressure-induced d−d shells repulsion and the sp−d hybridization weakening.