Crystal chemistry of neodymium oxyfluoride

Crystallography data reported in the literature for neodymium oxyfluoride has been summarized and analyzed. This analysis shows good agreement among most of the reported results, along with some inconsistent results. Neodymium oxyfluoride forms three crystal structures, all of which are derived from the cubic fluorite structure. There are two forms of stoichiometric NdOF, cubic and rhombohedral. The third crystal structure, tetragonal, forms when excess fluorine, relative to NdOF, is present and has a range of stoichiometry.