Structure and stability of finite gold nanowires

Finite gold nanowires containing fewer than $1000$ atoms are studied using the molecular-dynamics simulation method and the embedded-atom potential. Nanowires with a face-centered-cubic structure and (111)-oriented cross section are prepared at $T=0$ K. After annealing and quenching, the structure and vibrational properties of nanowires are studied at room temperature. Several of these nanowires form multiwalled structures of lasting stability. They consist of concentrical cylindrical sheets, and resemble multiwalled carbon nanotubes. Vibrations are investigated by diagonalization of the dynamical matrix. It is found that several percent of vibrational modes are unstable because of an uncompleted restructuring of initial fcc nanowires.