Considering ordered and coherent Al 3 Li clusters embedded in concentrated AlLi alloys as a model case, precipitation is investigated using Atomistic Kinematic Monte Carlo (AKMC) simulations. The free energy of clusters is extracted from simulations as a function of their size and monitored from the initial disordered state until coarsening. It is found that all components of cluster free energy vary linearly with the chemical potential of monomers, a property easy to implement into classical precipitation models.