RNiInDx compounds with R = Ce-Nd exhibit very short D-D distances of 1.5 A. The project aims at determination, whether this phenomena occurs for CePdIn1-xSnxDy compounds. Moreover, precise determination of deuterium positions and occupancies as well as magnetic structures will lead to verification of our theoretical model connecting the sequence of positions, where deuterium is placed with structural and magnetic changes after deuterium uptake.