A 35 ps portion of the Cs-hectorite, 1/3 water monolayer MD simulation animation (85–120 ps of the 800 ps simulation). Interlayer Cs+ are represented by orange spheres, while interlayer water molecules are represented by blue spheres. The greyish purple spheres symbolize the surface oxygen atoms of the lower clay layer surrounding this interlayer region. The rest of the atoms making up this lower clay layer, as well as all the atoms making up the upper clay layer, have been removed to improve the visibility of the interlayer region. Due to the periodic nature of the simulations, interlayer species which exit from one side of the simulation cell will reappear on the opposite side. The highlighted Cs+ (red) can be seen to display jump diffusion, while the highlighted water molecule (lighter blue) in the center of the simulation cell is characterized by continuous diffusional behavior as it moves from one Cs+ partial hydration shell to another. Another highlighted water molecule to the left can be seen visiting a surface cavity site for a short time. See Additional file 1 to access the animation.