Studying the properties of atom strands has involved considerable effort on the part of

experimental and theoretical researchers trying to compatibilize their experimental

results with the knowledge stemming from quantum mechanics. The development of

extensive simulations has been encouraged by two striking experimental features: first,

the existence of Au-Au distances (3.5-4 Å) unusually large as compared with what can

be expected on the basis of the results of quantum mechanical calculations; second, the

long- term stability of Au nanowires at room temperature, in many cases of the order of

seconds which is an extremely long time in relation to those characteristic of molecular

motion. Very recently Huang et al. [1] have measured the stability and breakdown of

nanojunctions at different stretching rates of the contact. Lifetimes were found

sensitive to stretching rates, with the finding that a rapid increase in the lifetime is

produced as the stretching rate is decreased. Typical lifetimes found with the stretching

rates values employed range between 1s and 10-3 s.