The growth behaviors of the Zn-doped different sized germanium clusters: A density functional investigation

Growth behaviors of the Zinc doped germanium clusters are systematically investigated by using density functional method. The growth-patterns, relative stabilities, charge-transfers, highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps and polarities of these clusters are discussed in detail. The threshold size of the Zn-encapsulated germanium clusters emerges as n = 10 while the icosahedral ZnGe12 cluster has stronger relative stability as compared to other sized clusters, which differs from the first-row unfilled d orbitals transition metal doped germanium clusters. The calculated fragmentation energies manifest that the magic numbers of relative stabilities for the Zn-doped germanium clusters are 5, 9, and 12. Natural population analyses show that charges transfer from the Zn to the germanium framework. It is worth pointing out that the HOMO-LUMO gap of the icosahedral ZnGe12 is remarkably large (3.159 eV) in comparison with other sized caged ZnGen (n = 1-11, 13) clusters.