Structural and electronic properties of pentagonal and hexagonal copper nanowires: First-principles investigation

By using first-principles calculations based on the density-functional theory, we have systematically investigated the equilibrium structure and the electronic properties of pentagonal and hexagonal copper nanowires (CuNWs). According to the stability and energetics analysis of pentagonal and hexagonal CuNWs, the staggered structures are energetically more stable than the corresponding eclipsed ones. And the preferred structures should be staggered ones which contain a linear chain along the wire axis passing through the center of the pentagons or hexagons, where each chain atom is located at a point equidistant from the planes of pentagons or hexagons. Electronic band structures and density of states .calculations show that the CuNWs with different structures exhibit metallic behavior. We also present a detailed analysis of the electronic structure of selected atoms from the projected densities of states (PDOS) analysis; our results show that the electronic properties are bulklike for atoms on the central chain. However, lower coordinated atoms on the surface of the nanowires have their electronic properties characterized by narrower d state shifted toward the Fermi energy. Finally, the density of charge revealed delocalized metallic bonding for all studied CuNWs.