New powder X-ray diffraction data of Ca12Al14O32F2 (C11A7f), a cementitious compound, were collected on a conventional X-ray powder diffractometer; the cubic cell parameter is a=11.96269(6) Å, volume 1711.93(2) Å3 (space group I-43d (No. 220)). The strongest lines are 4.887(100), 2.676(95), 2.992(46), 2.443(46), 2.185(37), 3.198(32), 1.599(26), and 1.941(25). Reported intensities are validated by Rietveld analysis. The new data consist of measured intensities and cover a wider 2θ angular range with respect to the calculated PDF 25-394 and the indexed PDF 36-678: experimental, calculated, and difference patterns are reported together with crystal-chemical considerations.

Precise X-ray powder diffraction data are given for two germanides, CoGe and Co5Ge7. The refined unit cell parameters for CoGe are a=11.630(1) Å, b=3.8014(3) Å, c=4.9347(3) Å and β=100.889(8)° (space group C2/m, Pearson symbol mC16) with volume of the unit cell 214.24(2) Å3; the figures of merit are M20=96, F30=77 (0.0085, 46). The refined unit cell parameters for Co5Ge7 are a=7.6262(4) Å and c=5.8017(5) Å (I4mm, tI24) with volume of the unit cell 337.42(3) Å3; the figures of merit are M20=204 and F22=130(0.0068, 25). The dependence on composition of the unit cell parameters of CoGe is discussed in terms of specific defect structures.

Plant surfaces are mostly covered with microscopic layers of wax which exhibit characteristic morphologies, visible under high magnification. Waxes belonging to three different types were investigated. Powder data of seven natural and three recrystallised waxes as well as of two isolated compounds are presented. The mainly crystalline nature of the studied plant waxes is proved. The correlation between morphology, chemical composition, and powder patterns is discussed.

X-ray powder data originally published for innelite—Na2Ba3(Ba, K, Mn)(Ca, Na)Ti(TiO2)2[Si2O7]2(SO4)2—were erroneously those of catapleiite. The new data reported here are compared with powder data calculated from the published structure. The cell is triclinic (space group P1, Z=1), a=14.71(1) Å, b=7.115(7) Å, c=5.379(4) Å, α=90.02(7)°, β=94.68(8)°, γ=98.43(9)°, V=555.0(6) Å3, F30=5.2(0.053,109).

CuInSeTe was synthesized by the melt and anneal technique. The compound crystallized in the chalcopyrite structure having space group I4¯2d with Z=4. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c, X-ray density and u parameter were calculated. These are a=0.5987(1) nm, c=1.1979(4) nm, Dx=5.96×103kg/m3, and u=0.2498. Atomic positions in the unit cell are proposed.© 2000 International Centre for Diffraction Data.

This paper presents the powder X-ray diffraction data of BaFI recorded using a Guinier diffractometer and Mo Kα1 radiation. BaFI stabilizes at standard temperature of 25 °C and standard-atmospheric pressure (STP) in the tetragonal structure (space group P4/nmm; No. 129) with lattice parameters a=4.660(1) Å and c=7.960(5) Å. Our observed pattern is different from the existing observed powder diffraction data reported in the PDF files 34-716 (Beck, 1976) and 31-139 (), but matches almost perfectly with the pattern calculated by us from the reported single crystal data ( and with the calculated data available in PDF file 70-0481. Further, our data provide a number of new Bragg peaks extending beyond the range of d values available in the existing PDF files.

The crystal structure of the Aurivillius compound Bi2BaTa2O9 prepared via the chemical route was determined by direct methods using EXPO97, and refined using the Rietveld method with conventional X-ray diffraction data. The structure was found to be tetragonal (space group I4/mmm, number 139) and Z=2, isomorphic of the Bi2BaNb2O9 reported by Blake and co-workers in the literature (1997). Two refinements were performed using the two asymmetry functions of DBWS-9807 (release 20/May/99). The unit cell for each case are: a=3.932 22(6) Å, c=25.5053(6) Å (RA) and a=3.932 50(7) Å, c=25.5069(6) Å (RCF). The differences for atom positions, interatomic distances and angles are in the range of one standard deviation. Final agreements factors are: Rwp=7.97%, S=1.84, RBragg=4.28%(RA), Rwp=7.98%, S=1.84, RBragg=4.30%(RCF). The occupancies of Ba and Bi in site 2b were refined but constrained to have their summation equal to 1.00. The same constraints were applied to the Ba and Bi of the 4e site. The results show that on site 2b there are 70% of Ba and 30% of Bi and on the site 4e there are 82% of Bi and 18% of Ba. The charge equilibrium is maintained for one standard deviation of the site occupancies.© 2000 International Centre for Diffraction Data.

The X-ray powder diffraction data for δ-Na2Si2O5 are reported. The sample was prepared from water glass solution applied to pressed powder tablets of finely ground quartz using a heating program with a maximal temperature of 700 °C. The crystallographic data for δ-disilicate obtained from a Rietveld analysis are: space group P21/n, a=8.3818(4) Å, b=12.0726(5) Å, c=4.8455(2) Å, β=90.303(5)°, V=490.31 Å3, Z=4, and Dcalc.=2.468 g/cm3.