menusearch results
results of search on CRYSTALLOGRAPHY JOURNALS ONLINE
22 citations found for Bell, A
Search for Bell, A in the World Directory of Crystallographers
Results 1 to 20, sorted by name:
research papers
High-resolution synchrotron X-ray powder diffraction and 29Si MAS NMR spectroscopy have been used to determine and refine the crystal structures of synthetic analogues of the mineral leucite.
research communications
Open 
access
access
Rietveld refinements show that the crystal structures of synthetic leucite silicate framework mineral analogues Rb2XSi5O12 (X = Ni, Mn) are isostructural with the Pbca cation-ordered structure of Cs2CdSi5O12.
inorganic compoundsOpen access
access
The apatite-type compound Ba5(AsO4)3Cl, pentabarium tris[arsenate(V)] chloride, has been synthesized by ion exchange at high temperature from a synthetic sample of mimetite (Pb5(AsO4)3Cl) with BaCO3 as a by-product. The results of the Rietveld refinement, based on high resolution synchrotron X-ray powder diffraction data, show that the title compound crystallizes in the same structure as other halogenoapatites with general formula A5(YO4)3X (A = divalent cation, Y = pentavalent cation, X = Cl, Br) in space group P63/m. The structure consists of isolated tetrahedral AsO43− anions (m symmetry), separated by two crystallographically independent Ba2+ cations that are located on mirror planes and threefold rotation axes, respectively. The Cl− anions are at the 2b sites (
symmetry) and are located in the channels of the structure.
symmetry) and are located in the channels of the structure.research papers
Crystal structures for synthetic analogues of the tectosilicate mineral leucite (KAlSi2O6) with stoichiometries of K2X2+Si5O12 (X = Fe2+, Co, Zn) and Rb2X2+Si5O12 (X = Mn) were refined from X-ray powder diffraction data. Structures refined in P21/c have ordered Si and X cations on the tetrahedral sites, whereas structures refined in 
have disordered Si and X cations. These leucite structures show an inverse relationship between the tetrahedral T—O distances and the intertetrahedral T—O—T angles.
have disordered Si and X cations. These leucite structures show an inverse relationship between the tetrahedral T—O distances and the intertetrahedral T—O—T angles.research papers
research papers
research papers
High-resolution synchrotron X-ray and neutron powder diffraction have been used to refine the crystal structures of synthetic analogues of the mineral leucite with a stoichiometry of Cs2CuSi5O12.
research papers (inorganic compounds)
inorganic compoundsOpen access
access
The fresnoite-type compound Sr2TiO(Si2O7), distrontium oxidotitanium disilicate, has been prepared by high-temperature solid-state synthesis. The results of a Rietveld refinement study, based on high-resolution synchrotron X-ray powder diffraction data, show that the title compound crystallizes in the space group P4bm and adopts the structure of other fresnoite-type mineral samples with general formula A2TiO(Si2O7) (A = alkaline earth metal cation). The structure consists of titanosilicate layers composed of corner-sharing SiO4 tetrahedra (forming Si2O7 disilicate units) and TiO5 square-based pyramids. These layers extend parallel to the ab plane and are stacked along the c axis. Layers of distorted SrO6 octahedra lie between the titanosilicate layers. The Sr2+ ion, the SiO4 tetrahedron and the bridging O atom of the disilicate unit are located on mirror planes whereas the TiO5 square-based pyramid is located on a fourfold rotation axis.
addenda and errata
Erratum to Acta Cryst. (1994), C50, 984-986.
inorganic compoundsOpen access
access
The apatite-type compound, pentastrontium tris[arsenate(V)] chloride, Sr5(AsO4)3Cl, has been synthesized by ion exchange at high temperature from a synthetic sample of mimetite [Pb5(AsO4)3Cl] with SrCO3 as a by-product. The results of the Rietveld refinement, based on high resolution synchrotron X-ray powder diffraction data, show that the title compound crystallizes in the same structure as other halogenoapatites with general formula A5(YO4)3X (A = divalent cation, Y = pentavalent cation, and X = F, Cl or Br) in the space group P63/m. The structure consists of isolated tetrahedral AsO43- anions (the As atom and two O atoms have m symmetry), separated by two crystallographically independent Sr2+ cations that are located on mirror planes and threefold rotation axes, respectively. One Sr atom is coordinated by nine O atoms and the other by six. The chloride anions (site symmetry 
) are at the 2a sites and are located in the channels of the structure.
) are at the 2a sites and are located in the channels of the structure.inorganic compounds
The Pbca structures of four leucite analogues have been refined by the Rietveld method using high-resolution synchrotron X-ray powder diffraction patterns collected on stations 2.3 and 9.1 of the Daresbury Synchrotron Radiation Source.
inorganic compounds
inorganic compounds
research papers
Reported here are two crystallographic structures of rapamycin in complex with the FK506-binding domain of Plasmodium falciparum PfFKBP35 at high resolution, in both its oxidized and reduced forms.
BIOLOGY | MEDICINE
Crystal structures of N-myristoyltransferase with four distinct Leishmania-selective small-molecule inhibitors identify key binding-site residues and suggest strategies to design compounds with increased affinity.
addenda and errata
A corrigendum to the paper by Ibberson et al. (2008), Acta Cryst. B64, 573-582
.
research papers
The crystal structures of phase II and the metastable phases III' and III of cyclohexanol, C6H11OH, have been determined using high-resolution neutron powder and single-crystal X-ray diffraction techniques. Phase II crystallizes in a tetragonal structure, space group 
, characterized by a hydrogen-bonded tetrameric ring motif. Phases III' and III are monoclinic, space groups P21/c and Pc, respectively, with molecules linked via hydrogen-bonded chains.
, characterized by a hydrogen-bonded tetrameric ring motif. Phases III' and III are monoclinic, space groups P21/c and Pc, respectively, with molecules linked via hydrogen-bonded chains.
abstracts
research papers (inorganic compounds)
