Abstract The β-modification of Li 3AlF 6 has been prepared by heating an appropriate mixture of LiF and AlF 3 at 820 °C under argon atmosphere and subsequently slow cooling it to room temperature. β-Li 3AlF 6 is isotypic to β-Li 3VF 6 and crystallizes inC2/c with a = 14.201(1)Å, b = 8.387(1)Å, c = 9.860(1)Å, and β = 94.07(1) °. The structural parameters have been refined by Rietveld analysis from powder data. A comparison of the structures of β-Li 3AlF 6 and β-Li 3TiF 6 is made for the analysis of a static Jahn-Teller effect within quasi-isolated [TiF 6] 3− octahedra. Calculations of the Madelung part of the lattice energy were performed to discuss the chemical bonding.