Molecular-dynamics study of the binding energy and melting of transition-metal clusters

Using constant-energy molecular-dynamics simulations, we have studied the binding energies and melting behavior of ${\mathrm{Ni}}_{\mathit{N}}$, ${\mathrm{Pd}}_{\mathit{N}}$, ${\mathrm{Au}}_{\mathit{N}}$, and ${\mathrm{Ag}}_{\mathit{N}}$ clusters (N=2–23) on the basis of the embedded-atom model and the second-moment approximation to the tight-binding method. The results show that the applicability of these two models, which have proved to be very useful for interpreting surface and bulk properties of transition metals, is questionable for systems with few particles. It is also shown that the kind of empirical data used in computing the parameters of the model potentials can crucially influence the cluster results.