  A surprising stability of the tube-like AuN (N = 26-28) has been shown using
the scalar relativistic all-electron density functional theory calculations,
forming another powerful candidate for the lowest-energy AuN competing with
those previously suggested space-filled structures. Unlike the icosahedral
"golden" fullerene Au32, these tube-like gold clusters may be closely related
to the synthesized single-wall gold nanotubes (SWGNT). The ground-state Au26
has a hollow tube-like structure constructed from the (6, 0) SWGNT, yielding a
high-symmetry D6d cage, based upon which the most stable Au27 and Au28 can be
obtained by capped one and two atoms, respectively.
