Data for the standard material NBS SRM 674, TiO2, were collected on two diffractometers: a) a Philips PW 1050/37 standard diffractometer of the Bragg-Brentano type equipped with a post diffraction curved Ge monochromator, b) a Stoe Stadi P diffractometer of transmission type equipped with a curved incident beam Ge monochromator. Both monochromators were set to select pure CuKα1 radiation. The reflection type instrument gives a much larger peak to background ratio than the transmission instrument, for which the background is much higher than with the reflection instrument. Rietveld refinements were carried out on both data sets with the programs DBWS-9807 and general structure analysis system (GSAS). The structural parameter of the oxygen atom of rutile depends neither on data set nor program, whereas, e.g., thermal displacement parameters seem to depend on both data set and program.

A powder neutron diffraction study has been undertaken for the titled compounds at room temperature. Data were analyzed using the Rietveld method. With increasing Nd content the unit cell has been found to contract very slightly, which is in accordance with the ionic radii of La3+ and Nd3+.

Powder X-ray diffraction (XRD) data were collected for a new phase of SrGd2O4. Analysis using the Rietveld method was carried out and it was found that the sample crystallizes in the orthorhombic symmetry with CaFe2O4 related structure. The lattice parameters are found to be a=12.0521(2) Å, b=10.1327(2) Å, c=3.4757(4) Å and Z=4. For X-ray data RF=4.9%, RB=7.6%, RP=8.1% and χ2=1.51. The structure can be described as an assembly of bioctahedron [Gd2O10] which are linked together by O2− anions and of dodecahedron of SrO8.

The ferroelectric liquid crystal material [4-[(4-methyloxyfenyl) carbonyloxyl] bifenyl-4′-yl]-(S)-2-methylbutoxypropionate containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit and two chiral carbons has been investigated by X-ray powder diffraction analysis at the 28 °C–105 °C temperature range. On cooling through the SmC temperature range, the layer spacing decreases from 28.3 to 27.7 Å with a small variation of average intermolecular distances. Lattice parameters of tetragonal and monoclinic crystalline phases occurring at lower temperatures have been determined.

The crystal structure of CaZr(PO4)2 was determined from conventional X-ray powder diffraction data using direct methods, and it was further refined by the Rietveld method. The structure was orthorhombic (space group P212121, Z=4) with a=1.448 76(4), b=0.672 13(1), c=0.623 47(2) nm, and V=0.607 10(3) nm3. Final reliability indices were Rwp=6.49%, RB=2.43%, and S=1.32. The Ca atom is sevenfold coordinated, and the Ca atom and surrounding oxygen atoms form a distorted capped octahedron with a mean Ca–O distance of 0.243 nm. The ZrO7 coordination polyhedron is a distorted pentagonal bipyramid with a mean Zr–O distance of 0.216 nm. CaO7, ZrO7, and PO4 polyhedra share edges to form infinite chains with the composition [CaO3ZrO3P2O8]12− along the [010]. Individual chains are linked together, forming a two-dimensional sheet parallel to (100). These sheets are stacked in the [100] direction to form a three-dimensional structure.

Li(1−2x)NixTiO(PO4) oxyphosphate powders were prepared from dilute solutions of NiCl2⋅6H2O, Li2CO3, (NH4)2HPO4, and TiCl4 in ethanol. The final temperature was 850 °C. Li(1−2x)NixTiO(PO4) oxyphosphates with 0≤x≤0.10 crystallize in the orthorhombic system with space group Pnma, while those with 0.10<x≤0.25 crystallize in the monoclinic system with space group P21/c.

New X-ray powder diffraction patterns for two cholesterol derivatives, cholest-4-ene-3,6-dione and cholest-4-en-3-one are reported in the range 0<2θ<115°. Both compounds crystallize in similar monoclinic cells in space-group P21, with unit cell parameters a=10.481(3) Å, b=8.0354(8) Å, c=14.677(3) Å, β=105.265(7)°, V=1192.5(4) Å3 for C27H42O2, and a=10.703(2) Å, b=7.8750(6) Å, c=14.660(3) Å, β=105.205(14)°, V=1192.4(4) Å3 for C27H44O. The patterns, confirmed by single-crystal studies, do not match the PDF 17-1144 and PDF 10-649. A fitting of the overall parameters was performed with Fullprof using the atomic parameters obtained from single-crystal studies.

X-ray powder diffraction data, high resolution electron microscopy observation and refined unit cell parameters for δ-Al2O3 prepared from γ-Al2O3 are reported here. The new lattice parameters were a=7.9631(7) and c=23.3975(23) Å with space group P41212 (No. 92). The new data provide evidence for the simple tripling of the unit cell of the starting γ-Al2O3 spinel.