A computational investigation of the Ni-doped Sin(n=1−8) clusters by a density functional method

The NiSin (n=1−8) clusters are investigated computationally using a Density Functional approach. Geometry optimizations of the NiSin (n=1−8) units are carried out under the constraint of well-defined symmetries at the B3LYP level employing a pseudopotential method in conjunction with Los Alamos double zeta basis sets. Consequently, the resulting total energies, natural populations, fragmentation energies, and equilibrium geometries of the NiSin (n=1−8) clusters are presented and discussed. Theoretical results show that the Ni atom in the small NiSin clusters absorbs on the surface site, and that the Ni atom in the NiSi8 cluster prefers being encapsulated into the Si frame. The most stable NiSin (n=1, 2) and NiSin (n=3−8) clusters correspond to the triplet and singlet spin configurations, respectively. The natural population of the Ni atom in the most stable NiSin (n=1−8) clusters varies from positive to negative. The relative stabilities are discussed; the calculated results reveal that the NiSi8 cluster is the most stable structure.