abstract: We will present a joint work with C. Le Bris and P.-L. Lions dealing with the definition of the energy of infinite set of atoms. Starting from the very simple case of a periodic lattice with classical energy, we will extend this kind of results to stochastic lattices andor quantum models of Thomas-Fermi type. In a second step, we will make the link between these kind of energies and macroscopic hyperelastic energies.