Stabilities of 3d transition-metal doped Si14 clusters

The geometries, electronic structures, and stabilities of MSi14 clusters (M = Sc–Ni) have been studied by using density functional theory. The results demonstrate that the cage composed of fourteen Si atoms can completely encapsulate a 3d transition-metal atom. The binding forces of MSi14 clusters mainly origin from the electrostatic and orbital interactions. In binding (or embedding) energy calculation, the Wigner–Witmer spin conservation rule is needed in the cases of CrSi14 and MnSi14. Among MSi14 clusters, only CrSi14 shows the highest stability and chemical inertness simultaneously, indicating that only 20-electron rule can be applied to MSi14 species.