By means of X-ray single crystal Weissenberg photographs, the crystal of the low-temperature solid form of 2-methyl-2-nitro-propanol, (CH3)2C(NO2)(CH2OH), has been determined and found to be of the monoclinic type, space group P21/c. The cell constants were refined from X-ray powder diffraction data: a=6.195(3) Å, b=19.116(7) Å, c=16.598(7) Å, and β = 90.12(2)° with Z = 12. The indexed pattern at 293 K is given.

Music, medicine, escape: Austria, Italy, America. As a very young man, Sigmund Weissmann, before he was 18, had seen the prosperous stability and direction of his youth disintegrate, had, through fortunate foresight and mature determination escaped potential disaster, and had found himself, essentially alone, in New York City. That was April 1939. Within 5 years, his early studies completed and military service over, his future had been established with crystallography, and even more particularly, that aspect of it which was related to the “pathology” of metals. He was to establish one of the first laboratories devoted to research of lattice defects and to lay the groundwork for what is now known as Materials Science. Contemporaneous with the operation of this laboratory and as an outgrowth of his own basic connection with the famous “Brooklyn Poly,” Weissmann included, among his manifold teaching, research, and consulting activities, the acceptance of a position as an editor of the Powder Diffraction File, the PDF. The PDF was then just large enough, just important enough and had just that suggestion of an important reach into the future to necessitate an equally important attention from a group of persons schooled and skilled in the most recent techniques of X-ray powder diffraction. Weissmann (metals), Ben Post (organics), of the Brooklyn Polytechnic Institute and J. V. Smith (minerals) (University of Chicago) were the first thus crystographically trained persons to oversee the PDF.

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.

X-ray powder diffraction patterns for 18 phases of 14 well-known explosives have been developed in our laboratory. Experimental patterns were obtained with an automated diffractometer for those phases for which samples were available. For phases with known crystal structures, patterns were calculated from the lattice and atomic positional parameters for comparison with the experimental patterns. Eleven of the experimental patterns have been included in Powder Diffraction File (PDF) Sets 40 and 42; four have been accepted but not yet issued. A final experimental pattern shall be submitted this year. In two other instances, since samples of sufficient quantity and/or quality were not available, calculated patterns alone are considered here. A review of the development of the crystallographic knowledge of these substances is given here together with a critique of the patterns and other known patterns of these phases.

A set of nine transition metal oxophosphorous compounds, consisting of four hypophosphites and five phosphites has been synthesized and studied using X-ray powder diffraction techniques. The compounds are α-Mn(H2PO2)2·H2O, Co(H2PO2)2 ·0.53H2O, MCl(H2PO2)2·H2O (M = Co2+, Ni2+), M2(HPO3)2·2H2O (M = Co2+, Ni2+), and M11 (HPO3)8(OH)6 (M = Zn2+, Co2+, Ni2+). Unit cells and X-ray powder patterns are reported.

The Metals and Alloys Indexes, published by the International Centre for Diffraction Data, contain four indexes. These are: (a) the alphabetical formula index (AFI); (b) the Pearson symbol code index; (c) the common name index; and (d) the Strukturbericht symbol index. These indexes (which contain metals, alloys, and related phases in the Powder Diffraction File) have been designed to be used independently or in conjunction with the Powder Diffraction File to facilitate the characterization of materials. All data in these indexes have been critically reviewed. The organization, selection of materials, and use of alphabetical formulas are similar to those of standard metallurgical references such as Pearson or Villars and Calvert. The arrangement of the AFI promotes systematic searches for chemical analogs and assists users in locating possible matches when only partial chemical information is available. The structural indexes aid in characterization by correlations to prototype and related structures. Some applications of the indexes are given here.

A novel algorithm has been developed for obtaining directly the applicable indices hkl for any interplanar spacing, dobs±Δdobs, of a triclinic phase with known unit cell parameters. This method is particularly useful for indexing back reflections for triclinic phases with unit cell volumes greater than 500 Å3.

The crystal structure of a new compound Li2Mg2(WO4)3 has been determined by means of X-ray powder diffraction. Li2Mg2(WO4)3 belongs to the orthorhombic system, with space group Pnma and the lattice parameters are: a = 5.1129 Å, b = 10.462 A, and c = 17.612 Å at room.temperature. Its measured density is Dm = 5.48 g/cm3, and each unit cell contains four formula weights.

X-ray powder diffraction data for buckminsterfullerene, C60 are reported. The crystal structure is a face-centered cubic unit cell with a = 14.165 (1) Å. The reference intensity ratio (I/Icor) is 2.20.

Bragg–Brentano X-ray powder diffractometry data and refined unit cell parameters are reported for a synthetic sample of dolerophanite, copper (II) oxysulphate [Cu2O(SO4)], prepared by heating AR copper (II) sulphate anhydrate in a muffle furnace at 725 °C. The data are compared with (i) two Debye–Scherrer patterns published by Mrose [Am. Mineral. 6, 146–153 (1961)]—for a synthetic sample and for a natural dolerophanite, the latter being pattern 13–189 in the ICDD Powder Diffraction File and (ii) a Debye–Scherrer pattern for a synthetic dolerophanite described by Borchardt and Daniels [J. Phys. Chem. 61, 917–921 (1957)]. A calculated pattern is also presented for the crystal structure of dolerophanite described by Effenberger [Monatschefte fur Chemie. 116, 927–931 (1985)]. The measured and calculated patterns reported here show reasonable internal consistency for both line positions and intensity data. While the agreement between these results and the data sets of Mrose is sound in terms of line positions, there is substantial disagreement overall between the intensity values given by the authors and those of Mrose. There is closer agreement between the intensities from the current study and those of Borchardt and Daniels.

Three new compounds of generalised formula [Cu(LIII)XY]·nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl–2-pyridyl–methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2′;6′,2″-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.

A two-stage procedure is described for quantitative phase analysis of multicomponent mixtures. Profile analysis of the diffraction pattern of a mixture of phases is done in stage one to obtain integrated intensities with higher accuracy. In stage two a structural refinement is done which yields a scale factor. The weight of a phase in a mixture is proportional to its specific scale factor. The two-stage method was found to be effective for the quantitative phase analysis of a mixture of minerals which always contain structural defects. The procedure was tested first by using two artificial mixtures and then it was applied to natural kaolin. The results obtained were more accurate than some of the other methods used for quantitative analysis; moreover, it can also be used with mixtures containing amorphous or undetermined phases.

X-ray powder diffraction is a convenient tool for monitoring changes in structural parameters due to modifications in sample composition and processing conditions. Due to the complexity of incommensurate modulated structures powder diffraction techniques have not been commonly applied. Programs ALSQ and QRIET have been produced to perform lattice parameter and structure refinements on incommensurate modulated materials with a displacive modulation model. In applying these programs to the Bi2Sr2CaCu2O8 superconductor which has this type of structure, it is shown that a decrease in the lattice parameters and an increase in the modulation vector occurs as the Ca content of the Bi-2212 phase, controlled by the use of the glass ceramic process, increases.

The silicate compound, K3Nb3O6Si2O7, has been synthesized by solid-state reaction. Single crystals were obtained; they crystallized with the hexagonal space group P2c. Refined unit-cell parameters are: a = 9.0377(3), c=8.0465(7)Å, V=569.18(5)Å3, Z=2, Dm = 3.84(4), Dx=3.851. Powder diffraction data are reported.

YBa2Cu3O7–x films were deposited by chemical vapor deposition (CVD) onto single-crystal MgO, single-crystal Al2O3, and polycrystalline Al2O3 substrates, characterized before and after annealing, and tested for their superconducting properties. The preferred orientation in the films was analyzed (i) with pole figures and (ii) by comparison of experimental x-ray powder diffraction patterns with those calculated for the material using the March–Dollase function to model the degree of preferred orientation. Preferred orientation was significant in as-deposited films, with March coefficients ranging from 0.1–0.5 (random orientation would have a coefficient of 1.0). The (006) pole figures of the films on single crystal substrates exhibited uniquely symmetric patterns. On single-crystal MgO before annealing, a minor secondary orientation of (006) poles in the film was observed in a pattern consistent with the symmetry of major crystallographic directions of MgO. On single-crystal Al2O3 after annealing, a “dual orientation” phenomenon was observed. The high-temperature anneal destroyed the orientation and superconducting properties of the CVD films deposited at high temperatures.

A Rietveld refinement of powder X-ray diffraction data of BiSbO4 is reported. The refined lattice parameters are a =5.4690(2), b =4.8847(3), c = 11.8252(6) Å, and β = 101.131(3)°. The powder data are compared with the PDF patterns designated BiSbO4 (30-177) and SbBiO4 (7-191).