CLUSTERS - TOOLS FOR STUDYING POTENTIAL SURFACES AND THEIR CONNECTION TO MOLECULAR-DYNAMICS

Clusters provide a particularly convenient laboratory for studying general characteristics of multidimensional potential surfaces and for relating the forms of those surfaces to the dynamics exhibited by the objects whose properties are governed by these surfaces. The multidimensional potentials of systems such as atomic van der Waals clusters and the binary clusters of alkali halide molecules can be represented very reliably, and now molecular van der Waals clusters of such species as CCl4 can be represented with considerable confidence as well. The extent of validity has been established for classical mechanical simulations, so that credence can now be given to the results of classical molecular dynamics simulations of clusters of second-row and heavier species. These illustrate finite-system counterparts of various kinds of phase changes, isomerization, and evolution of chaotic and ergodic behavior, as well as the effects on multidimensional potential surfaces of the character of the forces between pairs of particles.