Structures and dynamics of small alkali-halide clusters

The structure and phase behavior of small alkali-halide clusters were studied by constant-energy molecular dynamics and optimization. Premelting was found for (KCl)(n), n =6, 9, 12. A correlation of the energy of a number of alkali-halide clusters and their relative ionic radius was made to establish the condition for the preference of a given type of isomers as the more stable form. The isomerization dynamics of large ring-like LiBr, i.e., folding of larger rings to smaller ones with cube-like or close-packed structure, is consistent with the correlation.