“…Bulk Crystalline Lanthanum Trifluoride, 1. LaF 3 has been well characterized by a number of techniques, including single-crystal X-ray − and neutron diffraction, solid-state 19 F NMR − and 139 La NMR, , as well as variable-temperature 139 La nuclear quadrupole resonance (NQR) experiments. , Numerous structures of LaF 3 have been reported involving different space groups, cell dimensions, and atomic positions (see above references). The currently accepted structure is found in a combined X-ray and neutron-diffraction study on a single-crystal of LaF 3 by Maximov et al They reported a single lanthanum site and three distinct fluorine sites (denoted as F1, F2, and F3); however, the fluoride ions are known to undergo dynamic exchange, which may be largely responsible for the ionic conduction in LaF 3 . − , The local structure centered at the La site is depicted in Chart A.…”