The aim of this study is to elucidate the crystal structures of a series of microporous tin silicate materials after different degrees of ion exchange with strontium. The structural data will allow us to elucidate the mechanism of ion exchange and be the basis for computer modeling studies to predict stability, exchange behaviour and long term radiation damage effects. These materials are of potential interest for use in the nuclear industry for the selective removal of radioactive 90Sr from aqueous effluent waste streams.