Novel structures and properties of gold nanowires

The structures of free-standing gold nanowires are studied by using molecul ar-dynamics-based genetic algorithm simulations. Helical and multiwalled cy lindrical structures are found for the thinner nanowires, while bulk-like f ee structures eventually form in the thicker nanowires up to 3 nm in diamet er. This noncrystalline-crystalline transition starts from the core region of nanowires. The vibrational, electronic, and transport properties of nano wires are investigated based on the optimal structures. Bulklike behaviors are found for the vibrational and electronic properties of the nanowires wi th fee crystalline structure. The conductance of nanowires generally increa ses with wire diameter and depends on the wire structure.