  We present a Tight-Binding Molecular Dynamics investigation of the stability,
the geometrical and the electronic structure of suspended monatomic transition
metal chains. We show that linear and stable monatomic chains are formed at
temperature equal or smaller than 500 K for Au, 200 K for Ag and 4 K for Cu. We
also evidence that such stability is associated with the persisting sd orbital
hybridization along the chains. The study highlight fundamental limitations of
conductance measurement experiments to detect these chains in the breaking
process of nanowires.
