THE CRYSTAL-STRUCTURE OF DUGGANITE, PB3ZN3TE6+AS2O14

The crystal structure of dugganite, ideally Pb3Zn3Te6+As2O14, a 8.460( 2), c 5.206(2) Angstrom, V 322.6(2) Angstrom(3), space group P321, Z = 1, has been solved by direct methods and Patterson techniques, and re fined to an R index of 2.7% based on 636 unique reflections measured u sing MoK alpha radiation on an automated four-circle diffractometer. T he structure consists of heteropolyhedral sheets of edge-sharing TeO6 octahedra and PbO8 snub disphenoids, oriented parallel to (001). The s heets are cross-linked by AsO4 and ZnO4 tetrahedra, which share corner s to form an interlinked, two- and three-connected two-dimensional net parallel to (001). Cheremnykhite and kuksite are considered to be iso structural with dugganite, but with V and P respectively dominant at t he As site.