The perovskite iridates R2Ir2O7 are of fundamental interest because from R=Nd to Ho each member exhibits a metal insulator transition between T(MI)= 117 (Sm) and 141 (Ho) Kelvin, whilst Nd has a transition at 35K, appearing to be on the boundary between Sm and Pr which exhibits a spin-liquid ground state. Susceptibility measurements on the Eu compound have confirmed that the iridium atoms magnetically order at T(MI), but so far powder neutron diffraction measurements have been unable to measure any ordering on the iridium sublattice. The consistent behaviour of these materials despite the change in the rare-earth site implies that the change in properties is largely a geometric effect related to the size of the rare earth atom, and that Nd represents a critical point in this regime. We propose to determine the magnetic structure of the iridium sublattice in Nd2Ir2O7 and investigate possible modifications to the Nd sublattice at low temperatures by measuring on a single crystal using the superior optics available on the D10 instrument at the ILL.