Molecular dynamics simulations of hydrated Na-LSX zeolite at 300 K were performed with the explicit inclusion of the polarization of water. The Si/Al ratio of LSX is 1 and the number of water molecules per unit cell ranged from 0 to 224 to represent a range of hydration. The calculation results show that the dipole moments of water molecules increase with increasing hydration. By using the SPC-FQ water model instead of the SPC/E water model, the differential heat of adsorption showed similar trends in both models, whereas the differential potential energies between water-water and between water-zeolite are more sensitive to hydration. (c) 2005 Elsevier B.V. All rights reserved.