The density functional studies of the doped gold cages Au17M (MÂ =Â Cu, Ag, Li, Na, K)

It is found that the smaller atoms, such Cu, Ag, Li, and Na can be stably encapsulated in the Au17 cage, while the addition of the larger K atom prefers to locate in the outside of the cage. All the structures with M(M = Cu, Ag, Li, and Na) at the different off-center sites and K at all the outside the cage sites have almost the same energies, therefore, the internal site are almost the isoenergetic for the doped M(M = Cu, Ag, Li, and Na), while the outside site are almost the isoenergetic for the doped K.