LITHIUM ALUMINIUM BORATE, LiAl₇B₂O₁₇. By Göran Svensson and Johan Åhman, Inorganic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden. [gorans@guld.inoc.chalmers.se]

The most prominent features of this structure are isolated chains of edge-sharing AlO₆ octahedra running parallel to the crystallographic c-axis. These chains are connected by five-fold coordinated AlO₅ trigonal bipyramids and planar BO₃-groups. The lithium ions are located in the channels formed in the structure.

The title compound was obtained from a PbO/B₂O₃ flux, as a by product when LiAl₅O₈ was grown. Needle shaped, clear crystals with lengths up to 4 mm was obtained. The crystal structure was determined from X-ray data collected on an Enraf-Nonius CAD-4 diffractometer.

Two views of the Al₇B₄O₁₇-framework, boron and lithium atoms are omitted for clarity.