It and its larger neighbors are stable at room temperature and are known as "free-standing" cages--unattached to a surface or any other body, in a vacuum. "When deposited on a surface, the cluster may interact with the surface and the structure may change."
Wang and his co-workers suspect "that many different kinds of atoms can be trapped inside" these hollow clusters, a process called "doping." "These doped cages may very well survive on surfaces," suggesting a method for influencing physical and chemical properties at smaller-than-nano scales, "depending on the dopants."
Wang's group has not yet attempted to imprison a foreign atom in the hollow Au cages, but they plan to try.