The crystal structure of Ag2GeO3 was determined from laboratory X-ray powder diffraction data (Cu Kα1) using the Rietveld method. The title compound is orthorhombic with space group P212121, Z=4, unit-cell dimensions a=0.463 09(1) nm, b=0.713 93(2) nm, and c=1.040 79(3) nm, and V=0.344 10(2) nm3 . The final reliability indices were Rwp=5.58%, S=1.26, Rp=4.20%, RB=0.67% , and RF=0.35% . The GeO4 tetrahedra form infinite chains of [Ge2O6] along the a axis, with two tetrahedra per identity period of 0.463 nm. Individual chains are connected by Ag atoms, one-half of which are almost linearly coordinated by two O atoms and the rest are coordinated by three O atoms. The relatively short Ag-Ag distances of 0.299 to 0.339 nm indicate Ag(I)-Ag(I) interaction. This compound is isostructural with Ag2SiO3.

Slags sourced from a derelict zinc–lead–copper–silver–tungsten mine were examined for their bulk elemental composition and mineralogy. pH, oxidation–reduction potential, and the leachability of selected elements (sulphur, calcium, iron, copper, zinc, and lead) were assessed during a 130-day deionised water extraction conducted under oxic conditions. Slags were rich in silicon, iron, copper, zinc, and lead, hosted within minerals including quartz (SiO2), goethite [FeO(OH)], augite [Ca(Mg,AI,Fe)Si2O6], and lead (Pb0). Leachates from the slags increased in analyte concentration throughout the 130-day experiment, with iron, copper, zinc, and lead attaining >5 mg l−1 in some samples. These findings indicate that this pyrometallurgical waste should not be considered environmentally inert, as leachates emanating from them in the field might pose a significant risk to the environment.

Methods of chemical preparation and crystal data are reported for four new condensed phosphates: two hydrated cyclotriphosphates with a general formula SrMIP3O9⋅3H2O (MI=K+,Tl+) and their corresponding anhydrous cyclotriphosphates SrMIP3O9 (MI=K+,Tl+). The two hydrated condensed phosphates, SrKP3O9⋅3H2O and SrTlP3O9⋅3H2O, belong to previously investigated structure types. SrKP3O9⋅3H2O and SrTlP3O9⋅3H2O are orthorhombic, Z=4, space group Pnma, with respectively the following unit-cell dimensions: a=9.082(2) Å, b=8.133(2) Å, c=15.009(2) Å, M(20)=49, F(25)=61(0.0052;79) and a=9.115(7) Å, b=8.139(7) Å, c=15.221(2) Å, M(20)=285, F(30)=522(0.000 411;140). SrKP3O9 and SrTlP3O9 are monoclinic, space group P21/m or P21, Z=4, with, respectively, the following unit-cell dimensions: a=14.957(1) Å, b=8.372(1) Å, c=7.909(1) Å, β=102.27(1)°, M(20)=81, F(24)=95(0.000 025;92) and a=14.544(2) Å, b=8.639(1) Å, c=7.727(1) Å, β=102.05(1)°, M(20)=66, F(30)=78(0.003 098;125).

Chromite grains in ores from the Great Dyke, Zimbabwe, exhibit varying degrees of shearing when viewed by optical microscopy. High resolution diffraction data revealed that line broadening from powder samples of sheared chromites is largely due to two or more spinel phases with slightly different cell parameters, the number of phases increasing with the degree of shearing. The dominant or “parent” phase, with parameters ranging from 8.3123(2) to 8.2676(2) Å, constitutes 57% to 76% of most samples. The cell parameters of secondary phases are generally less than that of the parent phase by δa/a0 in the range −1.3 to −4.0×10−3, the difference again tending to increase with shearing. Most reflections for the parent phase are relatively sharp whereas those for the secondary phases exhibit line broadening that could be analyzed in terms of crystallike (domain) size and rms strain. The crystallite diameters, assuming spherical particles, are relatively large for the parent phases [260(2)–100(5) nm], while those for the secondary phases range from 165(70) to 70(25) nm. The rms strain is not large for any sample and is negligible or small for the unsheared and weakly sheared material. The microstrain in secondary phases is greater than that in the parent phase and tends to increase with shearing, the maximum rms strain being 1.6(3)×10−3. Two new forms of chromite in highly sheared material are reported, one with a slight (0.33%) tetragonal distortion and the other with a cell parameter of 17.561(2) Å, greater than that of normal spinel chromites by a factor of about 3/√2, and a lowering of symmetry from Fd3¯m to Fm3¯m. Changes in chemical composition, indicated by a range in cell parameter, are attributed to tectonics that affected much of the Great Dyke. The strain is partitioned between failure by brittle deformation of the chromite grains and stress-induced cation migration leading to cells with slightly different composition.

A novel sealed gaseous parallel plate avalanche chamber detector is described which is significantly less prone to discharges and can consequently achieve high gas gains at high counting rates. The detector has demonstrated stable gains greater than 104 at counting rates in excess of 107 counts/mm2 s.

Our X-ray powder diffraction data determine that UTeO4 has an orthorhombic unit cell with parameters: a=10.115±0.003 Å, b=10.706±0.002 Å, c=7.833±0.002 Å, and v=848±0.40 (Å)3, i.e., the cell volume twice as large as that of UTeO5. IR spectral studies show that UTeO4 and UTeO5 have almost an identical molecular symmetry. In UTeO4, the effective environment of U and Te remains nearly the same as in UTeO5 and the UO2 group is noncentrosymmetric and nonlinear with little or no interaction with equatorial oxygen. Frequencies of the characteristic stretching bands of UTeO4 are (cm−1): νas (O=U=O)=945, νs (O=U=O)=880, νs (Te–O)eq=818, νas (Te–O)eq=749, νas (Te–O)ax=649, νs (Te–O)ax=561.

The structure of two biomimetic copper complexes bis[4-benzylaldimino-3-methyl-1-phenyl-5-thio (seleno)pyrazolato]copper(II)—36 32N6X2Cu (where X=S, Se) have been studied and X-ray patterns of these compounds have been prepared using the Rietveld refinement technique. Both complexes crystallized in a monoclinic lattice, space group-C2/c(15). The unit-cell parameters are a=28.917(3) Å; b=7.000(2) Å; c=17.550(4) Å; β=106.869(1) (1) for C36H32CuN6S2 and a=29.126(6) Å; b=7.042(4) Å; c=17.228(2) Å; β=105.587(2) for C36H32CuN6Se2. Analysis of the copper and selenium K-edge X-ray absorption spectra (EXAFS) of these complexes show that a copper atom is in pseudo-tetrahedric ligand environment N2X2 with typical Cu–N bonds (R=2.00–2.01 Å) and significantly different Cu–S and Cu–Se bonds (R=2.27 Å and R=2.41 Å, respectively) because of different sulfur and selenium ion radii. © 2004 International Centre for Diffraction Data.

A novel porous material of composition Zn3(VO4)2⋅3H2O was prepared hydrothermally. The solid crystallizes in the hexagonal space group P6, with a=6.078 77(8), c=7.1827(2) Å, and V=229.857 Å3.

The powder diffraction pattern for p-Iodotoluene C7H7I at 293 K (P212121, No. 19, Z = 4) is given. The cell parameters found are a = 16.484(2) Å, b = 7.444(2) Å, c = 6.108(l) Å.