THEORETICAL-STUDY OF NACL CLUSTERS

In this paper we present the theoretical results obtained for (NaCl)n clusters with n less-than-or-equal-to 19. The calculations were perfor med using the ab-initio Perturbed-Ion (PI) model. That model was first developed for the study of ionic crystals and we have adapted it to s tudy clusters. Within the PI method we can determine the total energy of the cluster as a function of the position of the atoms in the clust er and minimizing the total energy with respect to the positions of th e atoms we can obtain the ground state geometry and other related prop erties. The results obtained for the equilibrium geometries are in goo d agreement with theoretical calculations using pair potentials. The s tudy of the relative stabilities of clusters with different numbers of molecules show that the clusters are specially stable for n = 4, 6, 9 , 12, 15, 16 and 18 molecules, in good agreement with experimetal resu lts.