Geometries and Electronic Properties of the Tungsten-Doped Germanium Clusters:? WGen(n 1-17).

Geometries associated with relative stabilities, energy gaps, and polarities of W-doped germanium clusters have been investigated systematically by using density functional theory. The threshold size for the endohedral coordination and the critical size of W-encapsulated Genstructures emerge as, respectively, n 8 and n 12, while the fullerene-like WGenclusters appears at n 14. The evaluated relative stabilities in term of the calculated fragmentation energies reveal that the fullerene-like WGe14and WGe16structures as well as the hexagonal prism WGe12have enhanced stabilities over their neighboring clusters. Furthermore, the calculated polarities of the WGenreveal that the bicapped tetragonal antiprism WGe10is a polar molecule while the hexagonal prism WGe12is a nonpolar molecule. Moreover, the recorded natural populations show that the charges transfer from the germanium framework to the W atom. Additionally, the WGe12cluster with large highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, large fragmentation energy, and large binding energy is supposed to be suitable as a building block of assembly cluster material. It should be pointed out that the remarkable features of WGenclusters above are distinctly different from those of transition metal (TM) doped Gen(TM Cu and Ni) clusters, indicating that the growth pattern of the TMGendepends on the kind of doped TM impurity. [ABSTRACT FROM AUTHOR]