December 1997 issue
cif-access (inorganic compounds)
cif-access (organic compounds)
The structure of YBa(Cu1.10Co0.90)O5 is constructed from the four bound layers BaO–(Cu,Co)O2–Y–(Cu,Co)O2. The mixed (Cu,Co) site atoms form distorted square-pyramidal pair-layers based on (Cu,Co)2O9, linked through their basal and apical O atoms.
The crystal structure of CdLn[B5O10] (Ln = La, Sm, Eu) contains planar infinite two-dimensional [B5O10]5− polyborate anions perpendicular to , separated by LnO10 polyhedra and Cd2O10 octahedral dimers. Three out of the five B atoms are four-coordinate, the other two have trigonal planar coordination.
The structure of the monophosphate Mg3Na3(PO4)3 contains three kinds of Mg–O polyhedra which form two types of infinite chain parallel to the shortest axis of the cell. The chains are connected with PO4 tetrahedra by corner-sharing to form a framework. The 1/3 substructure appears along the longest axis of the cell.
Rietveld refinement of a new zinc divanadate, Zn3(OH)2V2O7.2H2O, shows that it has a porous framework structure assembled from layers of Zn–O octahedra joined by pyrovanadate groups. Water molecules fill the large cavities.
Monoclinic Nb3SI7 crystallizes in a novel two-dimensional structure. The structure comprises [Nb3SI10]3− clusters which contain Nb triangles bicapped by μ3-I and μ3-S atoms. The clusters are linked to form dimeric units and these dimers are cross-linked to form layers of composition Nb3SI7.
Fe3W3N is isostructural with Westgren's cubic η-carbide structure and contains two sets of coordination polyhedra: NW6 octahedra, which share corners as in the pyrochlore structure, and Fe8 stellae quadrangulae, which also share corners on a structural lattice separate from that formed by the NW6 octahedra.
The crystal structures of Eu2Si5N8 and EuYbSi4N7, which both contain highly condensed Si–N networks, are reported.
The structure of K(CoII,Al)2(PO4)2 is built up from corner- sharing (Co/Al)O4 and PO4 tetrahedra to form intersecting tunnels running parallel to the unit-cell axes, with K atoms situated in the tunnels.