Adsorption properties of a nitrogen atom on the anionic golden fullerene   Au$_{16}^{-}$
  Using density functional theory, we examine a nitrogen-doped anionic golden cage (NAu$_{16}^-$). For the exohedral adsorption that is more stable than the endohedral doping, the bridge and hollow sites have larger binding energies than the atop sites by ~1 eV. When the N atom is adsorbed on the cage, electrons are transferred from Au$_{16}^-$ to the N atom. The transition between the exohedral and endohedral adsorption may occur thermally through a bridge site. In the infrared active vibrational spectra, exohedral doping causes greater intensities at higher frequencies than endohedral doping. 
Gunn Kim, Chan-young Lim, Seoung-Hun Kang, Young-Kyun Kwon
cond-mat.mes-hall cond-mat.mtrl-sci