Cover illustration: A simulated precession photo of the h0l plane showing the twin relationship in reciprocal space as a twofold rotation about a*. The radii of the circles indicate the intensities of the reflections. The main twin domain is drawn in open circles; the minor twin domain, with a twin fraction of 0.319 (2), is drawn in filled circles. The approximate primitive subcell in reciprocal space, covering both twin domains, is obtained by halving a*. See Lutz, Spek, van der Wiel & van Walree [Acta Cryst. (2005), C61, o300-o302].
Silver bismuth sulfide (3.5/7.5/13), Ag3.5Bi7.5S13, is the member with N = 8 of the homologous series [Bi2S3]2·[AgBiS2](N−1)/2. All octahedral metal positions in its structure show mixed occupancy between Ag and Bi.
The first rubidium gallium triphosphate has been synthesized by solid-state reaction and studied by single-crystal X-ray diffraction. It crystallizes in the non-centrosymmetric orthorhombic space group C2221, forming infinite [GaP6O20]∞ columns of PO4 and GaO4 corner-sharing tetrahedra along c, linked through the apices with GaO6 octahedra.
The crystal structure of Ba(ClO2)2·3.5H2O has been determined by single-crystal X-ray analysis at 150 K. The structure is layered and contains Ba2+ cations surrounded by O atoms in a bicapped square antiprismatic coordination environment.
Lithium aluminium germanium, AlGeLi, crystallizes in two cubic dimorphs. The structure of the F3m form has been confirmed by both powder and single-crystal X-ray diffraction studies. The second dimorph, not previously identified, adopts a disordered centrosymmetric structure with space group Fmm.
Rietveld refinement of a new strontium borophosphate shows that a BO4 tetrahedron, of symmetry , is surrounded by an array of four [PO4]3− tetrahedra. Sr atoms occupy sites coordinated by eight or nine O atoms.
The structure of lithium dioxomolybdenum arsenate oxide, Li(MoO2)2O(AsO4), consists of corner-shared Mo2AsO12 structural units which form layers. The Mo2AsO12 units result from the association of corner-shared AsO4 tetrahedra and Mo2O9 groups. The Li+ ions are located in the interlayer space.