In this proposal we would like to study the dynamics of interlayer species in hydrotalcite clay: (a) water and (b) terephthalate anions. In the case of water, the aim is to understand the dynamic timescales that accompany in particular reintercalation of LDH with water, as occurs during the formation of catalyst materials via rehydration of calcined mixed metal oxides. Use of both carbonate and terephthalate will allow us to quantify also the effect of gallery size, from around 7 to 14 Å, in this prototypical anionic clay. In each case there is direct comparison with simulation. We will also study the dynamics of terephthalate itself with the aim of relating directly the diffusion to the anion orientation as controlled by layer charge.