The crystal structure of kelyanite, (Hg2)6(SbO6)BrCl2 (original) (raw)

Abstract

The crystal structure of kelyanite, a rare mercury mineral that was found in oxidized mercuryantimony ores in the Kelyana deposit (Buryatia, Russia), has been determined. The preliminary formula of kelyanite was Hg34Sb3Cl3Br1O28 (assuming the presence of both the Hg1+ and Hg2+). In contrast to this assumption, kelyanite appears to contain only monovalent Hg and its revised formula is (Hg2)6(SbO6) BrCl2. Kelyanite is trigonal, space group P3, a = 13.560(4), c = 10.004(6) Å, V = 1593(1) Å3, and Z = 3. In the structure, Hg atoms form six crystallographically independent pairs [dumbbells of composition (Hg2)2+] with Hg-Hg distances of 2.482(3)-2.519(2) Å. The Hg and O atoms form O-Hg-Hg-O systems with Hg-O bond lengths of 1.98(3)-2.33(3) Å and HgHgO angles of 140.3(7)-168.3(9)°. Mercury atoms in the (Hg2)2+ dumbbells have additional coordination to O, Cl, and Br atoms [Hg-O 2.62(2) Å, Hg-Cl 2.68(1)-2.97(1) Å, and Hg-Br 3.00(1)-3.55(1) Å]. Three crystallographically independent Sb atoms are octahedrally coordinated by O atoms with Sb-O distances of 1.96-2.14 Å. The (Hg2)2+ dumbbells link the (SbO6) octahedra in a 3D structure.

Received: 2007-11-28

Accepted: 2008-4-10

Published Online: 2015-4-1

Published in Print: 2008-10-1