The crystal structure of hopeite, Zn3(PO4)2.4H2O
Abstract
<h2>Acta Crystallographica Section B</h2><h3>Structural Crystallography and Crystal Chemistry</h3><h3>0567-7408</h3> <h2>research papers</h2> Volume 31 Part 8 Pages 2026-2035 August 1975 <h2>The crystal structure of hopeite, Zn 3 (PO 4 ) 2 .4H 2 O</h2> A. Whitaker Acta Cryst. (1975). B31, 2026 The Crystal Structure of Hopeite, Zn3(PO4)z.4HzO By A. WmTAKER Department of Physics, Brunel University, Kingston Lane, Uxbridge, Middlesex, England (Received 13 January 1975; accepted 18 February 1975) The structure of hopeite, Zna(PO4)z.4H20, has been redetermined. It crystallizes in the orthorhombic system with cell dimensions a= 10.629 (2), b= 18"339 (3), c= 5-040 (1) .&. The space group is Pnma and there are four molecules in the unit cell. Least-squares refinement has been completed on three-dimen- sional data (1471 structure factors). The H atoms have been located and included in the refinement with an isotropic temperature factor of 4-0. The final residual is 6.8%. The structure consists of ZnO2(H20)4 octahedra, ZnO4 tetrahedra and PO4 tetrahedra, none of which are regular; these polyhedra share corners and edges. The mean (uncorrected) bond lengths are 2-099 (3) .A in the ZnO2(H2Oh octahedron, 1-963 (3) ,& in the ZnO4 tetrahedron and 1-537 (3) A in the PO4 tetrahedron. The thermal vibrations have been analysed