  Nanowires of different nature have been shown to self-assemble as a function
of stress at the contact between two macroscopic metallic leads. Here we
demonstrate for gold wires that the balance between various metastable nanowire
configurations is influenced by the microstructure of the starting materials
and we discover a new set of periodic structures, which we interpret as due to
the atomic discreteness of the contact size for the three principal crystal
orientations.
