Andreas Bohnsack, Gert Balzer, Mathias S. Wickleder, Hans U. Güdel and Gerd Meyer
Ternäre Halogenide vom Typ A₃MX₆. VII .
Die Bromide Li₃MBr₆ (M = Sm-Lu, Y): Synthese, Kristallstruktur, Ionenbeweglichkeit
Z. Anorg. Allg. Chem. 623, 1352-1356 (1997)                 

Abstract: The bromides Li₃MBr₆ (M = Sm - Lu, Y) are obtained from the binary components LiBr and MBr₃. They are crystallized with a substitution/addition variant of the AlCl₃-type of structure as was established from single crystal X-ray diffraction data for Li₃ErBr₆ (monoclinic, C2/m, Z = 2, a = 689.0(3), b = 1191.6(9), c= 684.2(6), b = 109.77(6)°) and by powder X-ray diffraction for the remaining bromides. They are isotypic with Na₃GdI₆ and Li₃ScCl₆, respectively. Impedance spectroscopy and ⁷Li-NMR spectroscopy show that the lithium ions are highly mobile.