Structural, electronic, and magnetic properties of the golden cage doped with a transition-metal atom, $M{\text{Au}}_{16}^{-}$ ($M=\text{Fe}$,Co,Ni), are investigated using trapped ion electron diffraction, photoelectron spectroscopy, and density-functional theory. The best agreement to experiment is obtained for endohedral $M@{\text{Au}}_{16}^{-}$ structures but with considerable distortions to the parent ${\text{Au}}_{16}^{-}$ cage. $\text{Fe}@{\text{Au}}_{16}^{-}$ and $\text{Co}@{\text{Au}}_{16}^{-}$ are found to have similar structures with $C_2$ symmetry while a $C_1$ structure is obtained for $\text{Ni}@{\text{Au}}_{16}^{-}$. The $4s$ electrons are observed to transfer to the ${\text{Au}}_{16}$ cage, whereas atomiclike magnetism due to the unpaired $3d$ electrons is retained for all the doped clusters.

• Received 19 December 2008

DOI:https://doi.org/10.1103/PhysRevB.79.033413