The synthesis, thermal behavior, crystallographic and X-ray powder diffraction data, and infrared spectral data for Ca8ZnSi4O16Cl2 have been determined. This compound is cubic with isolated silicate tetrahedra.

Indexed experimental powder diffraction patterns of Tl,Pb-1223 and Tl-1223 are presented with a method of determining good cell parameters for the former awkward case where c/a almost exactly equals 4. For Tl,Pb-1223, a = 3.814±0.001 Å, c = 15.267±0.005 Å, for Tl-1223, a = 3.814±0.001 Å, c = 15.302±0.005 Å, both tetragonal, space group P4/mmm.

The crystal structure data have been determined by X-ray diffraction for three rare earth magnetic materials, Nd2Co14B, Pr2Co14B, and Pr2Fe14B. The data were evaluated with several computer programs desingned for that purpose. The crystal structure for Nd2Co14B and Pr2Fe14D determined by X-ray diffraction agree with those obtained earlier by neutron diffraction.

X-ray powder diffraction patterns of orthorhombic- and rhombohedral-distorted perovskite PrNiO3 obtained at room temperature, 200°, 400°, 500°, and 600°C were analyzed and evaluated. An examination of the diffraction profiles shows essentially no line broadening indicating that the PrNiO3 powders synthesized by solid state reaction are well-crystallized and probably strain-free. The reliability and accuracy of the patterns were evaluated, and the figures-of-merit were in triple digits for the 500° and 600°C patterns of the rhombohedral phase and double digits for the more complex orthorhombic diffraction patterns recorded at room-temperature, 200°, and 400°C. Values of lattice parameters refined from the observed diffraction peak positions agree with those obtained from the Rietveld whole-pattern fitting analysis to within 1–2 × 10−4.

Reference X-ray diffraction patterns for the quarternary intermetallic superconductor phases of compositions LuNi2B2C and YNi2B2C are reported. Both materials were synthesized by the arc-melting technique. The patterns of these metallic phases exhibit preferred orientation in an ordinarily pressed sample, which was minimized through special specimen preparation. The observed intensities and the calculated values for both phases agree reasonably well with each other. Both compounds were refined in the space group I4/mmm, with a=3.4647(1) Å and c=10.6330(4) Å for LuNi2B2C and a=3.5271(1) Å, c=10.5361(7) Å for YNi2B2C.

X-ray diffraction experiments performed on the compounds FeIINbIVF6 and CoIINbIVF6 have shown that they crystallize in the rhombohedral system, space group R3¯ with a cationic ordering. Unit cell parameters were determined: a=5.4201(8) Å, c=14.072(2) Å, V=357.8(1) Å, Z=3 for FeNbF6, and a=5.351(2) Å, c=13.960(6) Å, V=346.2(2) Å, Z=3 for CoNbF6. Synthesis and powder diffraction data are reported.

Each of the RIR based methods for carrying out quantitative X-ray powder diffraction analysis are described and a consistent set of notation is developed. The so called “standardless” analysis procedures are shown to be a special case of the internal-standard method of analysis where the normalizing assumption is used. All analytical methods, other than the Rietveld whole pattern matching procedure, require the use of explicitly measured standards, typically in the form of RIR values. However, if only semi-quantitative results can be tolerated, the standards may be obtained by using published RIR and relative intensity values. The exciting new techniques of whole pattern fitting and Rietveld constrained quantitative analysis are also described in RIR notation and shown also to be forms of the internal-standard method with the normalization assumption. The quantitative results obtained from Rietveld quantitative analysis are derived from computed standards in the form of computed, normalized, RIRN values. The normalization assumption in Rietveld analysis allows the exclusive use of computed standards and comes as close to a “standardless” analysis as one can achieve: relying on the absence of amorphous material and on the validity of the structural models. Relationships are given for obtaining quantitative analysis from these RIRN values obtainable from the least-squares scale factors.

A nonlinear optical material 3-nitro–4-hydroxy–4′-bromobenzophenone has been characterized by x-ray powder diffraction. Experimental values of 2θ, corrected for systematic errors, relative peak intensities, values of d, and the Miller indices of 109 observed reflection with 2θ up to 90° are reported. The powder diffraction data have been evaluated, and the figures-of-merit are reported. The unit cell parameters least-squares refined from 34 nonoverlapping peaks of the orthorhombic compound with a P212121 space group are a = 7.619(7) Å, b = 27.651(5) Å, c = 5.650(7) Å, V = 1190.5(9) Å3, Z = 4, and Dx = 1.389 g/cm3.