Co(II) complexes with benzoic acid and ternary complexes with ligands benzoic acid and histidine/aspartic acid have been synthesized and characterized using various spectroscopic methods. On the basis of infrared, UV-visible spectra, and magnetic data the complexes were found to be having octahedral polymeric geometry. X-ray powder diffraction results show that the crystal systems of Co(II)-Ben and Co(II)-Ben-Hist complexes are triclinic with lattice constants a=15.58 Å, b=11.92 Å, c=4.33 Å, α=96.08°, β=104.68°, γ=88.46°, and V=774.15 Å3 and a=18.88 Å, b=17.01 Å, c=15.13 Å, α=93.15°, β=89.41°, γ=100.71°, and V=4768.75 Å3, respectively. The Co(II)-Ben-Asp complex is orthorhombic with lattice constants a=21.57 Å, b=15.06 Å, c=11.40 Å. α=β=γ=90°, and V=3703.38 Å3.

This paper reports a reference X-ray powder diffraction pattern for a high-pressure phase, CaCo2O4, which has been reported recently to have a large Seebeck coefficient. The structure of CaCo2O4 is orthorhombic with space group Pnma, a=8.789(2) Å, b=2.9006(7) Å, c=10.282(3) Å, V=262.43 Å3, and Dc=5.62 g/cm3. This phase crystallizes in the CaFe2O4-type structure and consists of an edge- and corner-shared CoO6 octahedral network. The reference pattern has been submitted to the Powder Diffraction File (PDF).

Two ternary phases, designated τ4 and τ5, were revealed in Al–Ti–Pt. The τ4-phase with equiatomic composition (i.e., AlTiPt) was found to have a hexagonal structure with a=4.3908(9) Å and c=5.4823(10) Å (space group P63/mmc), and the τ5-phase, forming in a compositional range between ∼Al14Ti58Pt28 and Al21Ti63Pt16, has a tetragonal structure (possible space groups P42nm, P-4n2, and P42/mnm). The refined lattice parameters for Al15Ti60Pt25 are a=9.7019(20) Å and c=5.0231(13)Å.

X-ray powder diffraction data for two ionic salts containing imidazole (Him) complexes of the magnesium(II) ion, [Mg(Him)4(H2O)2]Cl2 and [Mg(Him)6](NO3)2, are reported. Their crystal and molecular structures were determined by simulated annealing and full-profile Rietveld refinement methods. [Mg(Him)4(H2O)2]Cl2 was found to crystallize in the monoclinic system with space group C2/c, a=12.3980(3) Å, b=11.0234(2) Å, c=14.4691(3) Å, and β=107.024(1)°. [Mg(Him)6](NO3)2 crystallizes in the trigonal R-3 space group with a=b=12.4631(4) Å and c=14.9449(6)Å. Both species contain centrosymmetric complexes, and Mg is octahedrally coordinated by six imidazoles, as in [Mg(Him)6](NO3)2, or by four imidazoles and two water molecules, as in [Mg(Him)4(H2O)2]Cl2. Additional analytic, thermogravimetric, calorimetric, and spectroscopic characterizations were also performed.

Amino acids often cocrystallize with water molecules, which make them pseudopolymorphs of their anhydrous forms. In this work, we discuss in detail the hydrogen bond patterns in anhydrous L-proline and DL-proline and its pseudopolymorphic forms: L-proline monohydrate and DL-proline monohydrate. For this propose, the crystal structure of L-proline anhydrous was determined from synchrotron X-ray powder diffraction data and refined using the Rietveld method. Special emphasis is given to the role played by the water molecule in the hydrogen bond network observed in the crystalline structures.

X-ray powder diffraction data for ErH2−xDx formed by hydrogen (i.e., protium)–deuterium loading of Er metal are reported. Lattice parameters for the varying hydrogen–deuterium compositions followed Vergard’s law behavior. The cubic lattice parameter at room temperature for ErH2−xDx obeys a linear relationship according to the formula a=5.1287−1.1120×10−4⋅x, where a is the lattice parameter of the fluorite-type structure and x is the mole percent of deuterium. Microstrain measurements suggest a possible ordering of hydrogen and deuterium in the composition ErH1D1.

The National Institute of Standards and Technology (NIST) certifies a variety of standard reference materials (SRM) to address specific aspects of instrument performance for divergent beam diffractometers. This paper describes SRM 640d, the fifth generation of this powder diffraction SRM, which is certified with respect to the lattice parameter. It consists of approximately 7.5 g silicon powder specially prepared to produce strain-free particles in a size range between 1 and 10 μm to eliminate size-broadening effects. It is typically used for calibrating powder diffractometers for the line position and line shape. A NIST built diffractometer, incorporating many advanced design features, was used to certify the lattice parameter of the silicon powder measured at 22.5 °C. Both type A, statistical, and type B, systematic, errors have been assigned to yield a certified value for the lattice parameter of a=0.543 159±0.000 020 nm.

A new nickel zinc chromate with the composition of (NH4OH)3/2NiZn2Cr2O9⋅2H2O was synthesized by hydrothermal method. The compound was characterized by XRD, TGA, and XRF. X-ray powder diffraction data show that the crystal system of the title compound is hexagonal with space group R-3m, z=3, and unit-cell parameters: a=5.9794 and c=21.4875 Å.

Compound from the solid-solution NdSrNi1−xCrxO4−δ, 0≤x≤1, has been prepared using conventional solid-state method and was characterized by X-ray powder diffraction. The NdSrNi0.5Cr0.5O4−δ sample shows the adoption of the K2NiF4-type structure based on the tolerance factor calculation. X-ray diffraction analysis using the Rietveld method was carried out and it was found that NdSrNi0.5Cr0.5O4−δ compound crystallizes in tetragonal symmetry with space group I4/mmm. The lattice parameters are found to be at room temperature, a=3.8012(3) Å and c=12.4812(1) Å. For X-ray diffraction data, the reliability factors are RB=0.034, Rwp=0.089, , and χ2=1.17. Bond-valence sum calculations were performed for nickel and chromium. The changes in unit-cell parameters are discussed in terms of oxygen stoichiometry and transition metal (3d) oxidation state from the perspective of the Brown bond-valence sum calculation theory.

Please note the copyright statement should read: Her Majesty the Queen in Right of Canada, as represented by the Minister of National Defence, [2010]. © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale, [2010].