  Morphology and its stability are essential features to address
physicochemical properties of metallic nanoparticles. By means of Molecular
Dynamics based simulations we show a complex dependence on the size and
material of common structural mechanisms taking place in mono-metallic
nanoparticles at icosahedral magic sizes. We show that the well known Lipscomb
s Diamond Square Diamond mechanisms, single step screw dislocation motions of
the whole cluster, take place only below a given size which is material
dependent. Above that size, layer by layer dislocations and/or surface peeling
are likely to happen, leading to low symmetry defected motifs. The material
dependence of this critical size is similar to the crossover sizes among
structural motifs, based on the ration between the bulk modulus and atomic
cohesive energy.
