MOLECULAR DYNAMIC STUDY OF HYDROPHILICITY OF THE NACL MOLECULE

The NaCl molecule is represented as a physical dipole in which the dis tance between the ions equals that in the crystal lattice of NaCl. The water molecules, initially uniformly distributed in the sphere around the NaCl molecule, in I or 2 ps form a hydration shell around the pos itively charged sodium ion, leaving the negatively charged chloride io n naked. When the number of water molecules around the sodium ion reac hes 14, the NaCl(H2O)(14) cluster becomes sensitive only to thermal pe rturbations that are due to the librational motion of water molecules. If is shown that the dependence of the cluster volume on the number o f wafer molecules in the cluster does not admit simple linear approxim ation.