First-principles investigation of monatomic gold wires under tension

Abstract

Ab initio pseudopotential total-energy calculations on infinite monatomic chains of Au are performed within density functional theory. We use the density functional perturbation theory to study the phonon spectra of these gold wires as a function of strain. Our results show that there does not seem to be a range of strain for which the linear chain is stable, contrary to what was stated by Ribeiro and Cohen [Phys. Rev. B 68 (2003) 035423]. For low strain, the zigzag chain is the stable geometry; while for higher strain, the chains with two or more aligned gold atoms are found to be more stable. At the limit between these two regimes, we predict a transition structure (an asymmetric zigzag chain) to be the most stable.