Novel analysis of dynamical complexities in finite-size systems*

Finite-size systems present additional complexities in their dynamical behavior as compared to extended systems. The analysis and characterization of these added complexities demand new tools and descriptors. Here we present the notion of Dynamical Degrees of Freedom (DDF) and illustrate its utility in the understanding of the complex stage-wise meltinglike transition in bimetallic Ni/Al clusters. The similarities and differences between the energy-driven changes in the DDF in bimetallic clusters and their one-component counterparts will be pointed out. The discussion will also include more traditional descriptors, such as caloric curve, RMS bond-length fluctuation, and heat capacity.