Molecular polarizability of Scn, Cn and endohedral Scn @ Cm clusters

The interacting induced dipoles polarization model implemented in the program POLAR is used for the calculation of the molecular dipole-dipole polarizability alpha. The method is tested with Sc-1-Sc-7, Sc-12, Sc-17, Sc-74, C, C-12, C-60, C-70, C-82-fullerene, Sc@C-60, Sc@C-82, Sc-2@C-82. Sc-3@C-82, C-1-C-6, C-10, C-13, C-16, C-19, C-22, C-24, C-42, C-54, C-84 and C-96-graphite clusters. The polarizability is an important quantity for the identification of clusters with different numbers of atoms and even for the separation of isomers. The results for the polarizability are of the same order of magnitude as reference calculations performed with another pro-ram based on the same formulation. The bulk limit for the polarizability is estimated from the Clausius-Mossotti relationship. The polarizability trend for these clusters as a function of size is different from what one might have expected. The clusters are more polarizable than one might have inferred from the bulk. Previous theoretical work has yielded the same trend for small Si-n, Ge-n, and GanAsm clusters. However, previous experimental work has yielded the opposite trend for larger Si-n, GanAsm and GenTem clusters. At present, the origin of this difference is problematic. One might argue that smaller clusters need not behave like those of intermediate size. The high polarizability of small clusters is attributed to dangling bonds at the Surface of the cluster, which resembles a metallic cluster.