Crystal Structure of Li6BeF4ZrF8

The crystal structure of Li6BeF4ZrF8 has been determined by x-ray diffraction. The tetragonal unit cell, having a=6.57, c=18.62 Å, contains four formula weights; the space group is D4h19—I41amd. Discrete BeF42— and ZrF84— ions are connected by shared Li+ ions. The BeF42— tetrahedron is quite regular with a Be–F distance of 1.57±0.01 Å; the ZrF84— dodecahedron has two independent Zr–F bonds of 2.05±0.01 Å and 2.16±0.01 Å, and deviates considerably from the shape predicted by theory.