Acta Crystallographica Section B

Structural Science

Volume 55, Part 2 (April 1999)

research papers

Acta Cryst. (1999). B55, 165-169 [ doi:10.1107/S0108768198012312 ]

Iodo-oxyapatite, the first example from a new class of modulated apatites

P. Alberius Henning, S. Lidin and V. Petrícek

Abstract: Iodo-oxyapatite [pentadecacalcium iodide oxide nonaphosphate, Ca₁₅(PO₄)₉IO] was synthesized by a flux method and the structure was solved from single-crystal X-ray data. The crystal structure was refined in the space group P6₃/m [a = 9.567 (1), c = 20.754 (2) Å and Z = 2] to wR on F of 0.0459. Iodo-oxyapatite has a typical hexagonal apatite structure but the unit cell is tripled along the hexad owing to ordering of the iodide and oxide ions along this direction.