In this work, we report updated structural data, obtained by single-crystal X-ray diffraction, on the binary fluoride Nb 6 F 15 as well as measurements of 19 F NMR over the temperature range 100–300K, and EMR measurements over the temperature range 4–300K. Nb 6 F 15 is built up from Nb6F12iF6a octahedral cluster units sharing all apical fluorine ligands to form linear Nb–F a –Nb interunit bridges (F i : inner fluorine located in edge-bridging position, F a : apical fluorine located in terminal position). The 19 F NMR results showed two resonance lines. One line corresponds to the inner fluorine F i in the (Nb 6 F 12 ) −3 cluster core. The second 19 F NMR line corresponds to the apical F a . The shift of the NMR signal from F i depends on the temperature and exhibits a Curie type behavior, while the position of the NMR signal from F a is temperature independent. EMR measurements show a single Lorentzian line. The temperature dependence of the inverse of the intensity of the EMR line shows a Curie–Weiss behavior and an onset to an antiferromagnetic (AF) order at 5K.