  We study in detail, by experimental measurements, atomistic simulations and
DFT transport calculations, the process of formation and the resulting
electronic properties of atomic-sized contacts made of Au, Ag and Cu. Our novel
approaches to the data analysis of both experimental results and simulations,
lead to a precise relationship between geometry and electronic transmission. We
reestablish the significant influence of the number of first neighbors on the
electronic properties of atomic-sized contacts. Our results allow us also to
interpret subtle differences between the metals during the process of contact
formation as well as the characteristics of the resulting contacts.
