The structure and phase behavior of small alkali-halide clusters were
studied by constant-energy molecular dynamics and optimization. Premel
ting 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 lar
ge ring-like LiBr, i.e., folding of larger rings to smaller ones with
cube-like or close-packed structure, is consistent with the correlatio
n.