Redetermination of the crystal structure of hanawaltite

The crystal structure of hanawaltite, Hg6+Hg2+O3Cl2, a 11.796(4), b 13.890( 6), c 6.471(2) Angstrom, V 1060.2(6) Angstrom(3), space group Pbma, Z = 4, has been refined toan R index of 0.049 on the basis of 662 merged, observed reflections. The crystal structure has two distinct layers; a Hg+-Cl-O lay er consistingof ribbons of [Hg-Hg](2+) dimers resembling the configuration in thecalomel structure and a Hg2+-Hg+-Cl-O layer with alternating mercurou s and mercuric oxychloride chains.