Photoionization of the Zn@C$_{60}$ endofullerene: Atom-fullerene ground-state orbital hybridization of d-d character

A detailed theoretical study of the subshell photoionization of Zn endohedrally confined in C$_{60}$ has been performed. The fullerene molecular core of sixty C$^{4+}$ ions is modeled by a classical jellium smearing, while the delocalized cloud of 240 carbon valence electrons, \textit{plus} the encaged Zn atom placed at the center of the cage, are treated in the time-dependent local density approximation (TDLDA) [1]. A powerful hybridization of the Zn 3d state with the 2d orbital near the low end of C$_{60}$ electronic band are unraveled. Cross sections for these hybrid states at both low photon energies, overwhelmed by electronic collective motions, and high energies of dominant single-electron behavior are presented. The results exhibit rich structures and are radically different from the cross sections of free atomic or free fullerene states participating in the hybridization process.\\[4pt] [1] M.E. Madjet et al., \textit{Phys. Rev. }A \textbf{81}, 013202 (2010).