It is known from NMR experiments that silanol defects are among the most common points defects encountered in zeolites. These defects are modeled through a silicon atom vacancy, resulting in a "silanol nest" initially proposed by and integrated in silicalite-1 by Cailliez and Trzpit to study its influence on water intrusion. We have chosen here to introduce 1 or 4 silanol nests in each unit cell of the silicalite-1 model, and 0.25 or 0.5 nests in each unit cell of the chabazite model (see Figure ). We decided to focus our attention on these two zeolites to disentangle the role of silanol defects on the thermodynamic of electrolyte intrusion, from that of pore size. In the silicalite-1 model, we selected and removed from the framework a silicon atom at the intersection between a straight and a zigzag channel (T1 site). For chabazite, we chose to remove a silicon atom that was common to both large and small cages. The resulting four dangling oxygen atoms were then saturated by a hydrogen atom and the O-H bond length (0.9572 Å) was set to the same value as in the TI4P water molecule model, as well as the Si-O-H angle set to 109.5 • . In real zeolites, the silanol defects are assumed to be randomly distributed. We discard here frameworks having irregular defect distribution because the use of periodic boundary conditions would lead to spurious effect, but instead use a regular spacing of the defects. It must be mentioned here that we are not exploring high defect content models because it has been proven that silicalite-1 model containing only one defect per cell provides a reasonable description of the thermodynamics of water intrusion.