The thermodynamically driven surface growth on Li and Na was examined in the framework of a coupled ReaxFF/GCMC approach. To determine the minimum energy of the respec-tive structures, we adopted the developed and validated ReaxFF force field potential for Li and Na. Different nanoparticle shapes (∼1000 atoms) were used as an initial structure for the GCMC simulation to consider the influence of the various crystal facets and edges.