INSTANTANEOUS NORMAL MODE ANALYSIS AND COEXISTENCE PHENOMENA IN SMALL CLUSTERS

The results of instantaneous normal mode analysis are considered in detail for small clusters of seven, eight and 13 atoms interacting via a Lennard-Jones potential. When short-time averages of the phonon spectrum are considered new insight is obtained into the dynamics of these systems, especially with reference to the coexistence of solid-like and liquid-like forms. The results are entirely consistent with theories that relate the detailed dynamics, as obtained from simulation, with the minima and transition states on the calculated potential-energy surfaces.