Abstract |
Cubic and hexagonal symmetries are observed in molecular dynamics simulations of lithium chloride unconstrained nanoclusters, using the Born-Mayer-Huggins (BMH) potential model. Phase changes between the two solid phases, and solid-liquid coexistences, are studied for LiCl clusters with a number of ions ranging from 1000 to 5292. A stability analysis of the clusters and bulk systems, at 0K, is presented, using the BMH and the Michielsen-Woerlee-Graaf (MWG) potential models. The cubic structure from the BMH model is slightly more stable than the hexagonal one for cluster sizes between 1000 and similar to 10 000 ions. For higher cluster sizes and bulk LiCl the opposite is true. Moreover, at 0 K, the bulk cubic phase from the MWG potential is significantly more stable than the hexagonal one. Thus, the BMH potential model seems unrealistic for large clusters and the bulk as far as a comparison with experiment is concerned. Finally, a fairly good correlation of the simulation results is obtained by means of a theoretical model recently reported by us. |