The geometrical structure, frequency and electronic properties of the NiMgn(n=1—12) clusters have been studied with the generalized gradient approximation (GGA) based on the density functional theory (DFT) with the consideration of spin multiplicity. The results indicate that: when n is 1 or 2, the spin multiplicity of the ground state structures of the clusters is triplet while it is singlet from n≥3. The ground state structures of the host clusters are changed obviously due to the encapsulation of Ni atom for n≤8, the growth patterns of the ground state structures of the NiMgn clusters are dominated by the trigonal bipyramidal, as well as the octahedron structures. The evolution behaviors of the ground state structures based on the trigonal prism of the host clusters are partly modified from n≥9. The Ni atom completely falls into the center of the host clusters as n≥6. The doping of Ni atoms increases the average binding energy, but reduces the energy gap of the host clusters. n=4, 6 and 10 are the magic numbers. The 3d and 4p orbitals of the Ni atom for different sized clusters play distinct roles in the s-p-d orbital hybridization. The NiMg6 cluster with higher symmetry Oh not only possesses improved stability, but also has the smallest energy gap (just about 0.25eV) of all of the NiMgn clusters.
Equilibrium geometries, charge distributions, stabilities, and electronic properties of the Cu-adsorbed (SiO2)n (n=1—8) clusters are investigated by using the density functional theory in the generalized gradient approximation for exchange-correlation functional. The results show that the Ag atom preferably binds to silicon atom with dangling bond, and the incoming Ag atoms tend to cluster on the existing Ag cluster leading to the formation of Ag islands. Therefore the ability for Si to lose electron is weaker, while the ability for Si to gain electron is stronger. In addition, the energy gaps between the highest occupied and the lowest unoccupied molecular orbitals remarkably decrease compared with the pure (SiO2)n (n=1—8) clusters, eventually approaching the near infrared radiation region.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.