Our recent work using fluoro- starting materials in fluoro-media in combination with framework forming species such as T(O,F, OH)n (T = Si, P, B and other tetrahedral-forming elements) and M(O,F,OH)n (M= typically a transition metal, n=4-8) has demonstrated the existence of new classes of material where the framework is constructed of oxo, hydroxo and fluoro containing units. A limitation of SXD determined structures is the impossibility in distinguishing fluoride and hydroxide especially for sites that may be partially occupied by both. However, we believe that powder neutron diffraction (or more probably PND combined with SXD) will provide sufficient additional information to unequivocally allow us to assign the sites to F, OH and/or determine the proportions of these two monoanions on a mixed site.