Density functional calculations of the structures and binding energies of Ni_2C_n clusters (n=7-11)

摘要

The study of metal carbide clusters, particularly those containing transition metal (TM) atoms, has attracted much attention, especially since the discovery of the metallo-carbohedrenes ("met-cars:).~1 It has been found that the 3d TMs exhibit a wide range of interactions with C at the cluster level. For example, erly 3d TMs easily form met-cars, while late 3d TMs have no such tendency (see Ref. 2, and references cited therein). By contrast, only late 3d TMs act as catalysts in the production of C nanotubes.~3 These findings have motivated the study of small TM-C species in the hope that it will provide insight into TM-C growth mechanisms and the TM-catalyzed growth of novel all-C nanostructures.