The nature and distribution of vacancy defects in wüstite, Fe(1-x)O, is an important problem because the structural and dynamical properties of the mineral - both of which are affected by defect distributions - are implicated in key geophysical processes at the core-mantle boundary. A difficulty faced by traditional crystallographic studies of wüstite has been that the problem of vacancy distributions is really a question of local, rather than average, structure. This proposal aims to address the problem using total scattering and reverse Monte Carlo (RMC) techniques to build realistic three-dimensional atomistic models of wüstite that are consistent with both average and local structure information. The local magnetic structure of low-T antiferromagnetic Fe(1-x)O is thought to be affected by vacancy clusters, and we will determine this magnetic structure from our RMC analysis.