bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallographic study of the mineral ferroan clinozoisite from three localities of Northern Greece
Authors: Stergiou A. C. , Gioureli D. K.
Published: January 2013

Samples of the mineral ferroan clinozoisite from three localities of Greece (Paranesti-Drama, Xanthi, and Petritsi-Serres), with chemical formula Ca2Al3−xFexSi3O13H (x=0.55, 0.58, and 0.46, respectively), were measured by X-ray powder diffraction, using CoKa radiation. The PDF and bibliographic information were used in order to identify additional phases in the samples. Refinement combined with PDF resulted in the following: ferroan clinozoisite (100%) for the first sample, ferroan clinozoisite (97%) and malladrite (3%) for the second one, and ferroan clinozoisite (75%), clinopyroxene (20%), and malladrite (5%) for the third one. The crystal structure refinement was performed by the “Powder profile analysis (Rietveld)”. P21/m space group was chosen for the ferroan clinozoisite phases, with unit cell constants a=8.8919(5) Å, b=5.6260(3) Å, c=10.1570(6) Å, β=115.418(3)° (Paranesti), a=8.8944(7) Å, b=5.6394(4) Å, c=10.1626(8) Å, β=115.400(5)° (Xanthi) a=8.8965(8) Å, b=5.6372(4) Å, c=10.1595(9) Å, β=115.411(6)° (Petritsi) almost similar for the three samples, while the final R-p factors were 0.069, 0.064, and 0.063, respectively.
Inorganic crystal structures from powder data—A retrospection
Authors: Smrčok L’ubomír , Mailing Ján
Published: January 2013

More than 10 000 inorganic structures based on both X-ray and neutron powder diffraction data were extracted from the ICSD database and analyzed considering overall trends, cell symmetries, occurrence of the space groups, complexity, precision and reliability of reported data. It was found that the major amount of structures belong to higher symmetries and have 2–5 atoms in the asymmetric unit. Less than 35% of the e.s.d.'s of atomic coordinates is ≤10−3 and 10−4 or better was reached in only 5% of cases. Approximately one-quarter of papers contain possibly inaccurate atomic coordinates or interatomic distances. A short review of journals publishing structures derived from powders is also given.
Crystal structure and powder data of davidite-type La2Ti10.27Ga9.63O38
Authors: Meden A. , Kolar D. , Škapin S.
Published: January 2013

The structure type of La2Ti10.27Ga9.63O38 was revealed by a search-match using the PDF. A successful Rietveld refinement (Rp=8.9, Rwp=13.3, RB=4.20) confirmed the structure to be rhombohedral (space group R3¯, No. 148) with the refined unit cell parameters a=9.1878(1) Å, α=68.458(1)°, and V=646.374(1) Å3. The structure is compared to other compounds of the davidite type, and the observed and calculated powder data are given.
Neutron powder diffraction data for low- and high-temperature NASICON phases of LiM2(PO4)3 (M=Hf, Sn)
Authors: Morin E. , Le Mercier T. , Quarton M. , Losilla E. R. , Aranda M. A. G. , Bruque S.
Published: January 2013

The new diffraction patterns of the low- and high-temperature phases of Li0.87Hf2.032(PO4)3 and LiSn2(PO4)3 are given and indexed on the basis of a structure refinement from neutron powder data using Rietveld method. The two isotypic compounds present a reversible phase transition: triclinic (LT, space group P1¯) ⇄ rhombohedral (HT, space group R3¯c) which proceeds by topotactic distortion of the structural skeleton.
X-ray powder diffraction data for the ternary phases W5As2.5P1.5 and Ni4Nb5P4
Authors: Bénard-Rocherullé P. , Députier S. , Charki F. , Guérin R.
Published: January 2013

The two ternary phases W5As2.5P1.5 and Ni4Nb5P4 have been investigated by X-ray powder diffraction. Precise data for the two compounds were collected using CuKα1 radiation over the range 11°–140° 2θ. Unit cell refinements (space group I4/m) led to a=9.4729(3) Å, c=3.2414(2) Å (Dx=13.16 gcm−3) with M20=127, F30=91(0.0092,36) for W5As2.5P1.5 and a=9.9304(4) Å, c=3.5243(3) Å (Dx=7.87 gcm−3) with M20=179, F30=138(0.0068,32) for Ni4Nb5P4.
X-ray powder diffraction data for two new N-substituted 3,4-dihydrospiro-2(1H) quinolines
Authors: Henao J. A. , Palma A. , Kouznetsov V. V. , Delgado J. M.
Published: January 2013

The X-ray powder diffraction patterns for two N-substituted tetrahydroquinolines are reported. N-(α-Chloroacetyl)-6-methoxy-3,4-dihydro-4-methylspiro[cyclohexane-1′,2(1H)quinoline], C18H24ClNO2, and N-(α-chloroacetyl)-6-chloro-3,4-dihydro-4-methylspiro[cyclohexane-1′,2(1H)-quinoline], C17H21Cl2NO are monoclinic, with refined unit cell parameters a=1.4471(3), b=0.9600(4), c=1.1948(3) nm, β=93.21(2)°, V=1.6573(6) nm3, Z=4, Dx=1.29 gcm−3, and a=1.4487(3), b=0.9878(2), c=1.1390(2) nm, β=91.66(2)°, V=1.6294(4) nm3, Z=4, and Dx=1.32 gcm−3, respectively, with space group P21/n (No. 14).

Key words: powder diffraction data, spirotetrahydroquinolines.
An X-ray diffraction study of AgNbO3 and comparison with NaNbO3
Authors: Darlington C. N. W.
Published: January 2013

The powder diffraction pattern of the perovskite AgNbO3 has been measured using CuKα1 radiation with an incident beam focusing monochromator to eliminate the Kα2 component. Indexing the pattern shows that the multipartite cell is 2×2×4 times that of the pseudocubic subcell. Comparison is made with the diffraction pattern of NaNbO3, which has a similar multipartite unit cell. There are strong similarities, but close inspection shows that the structures are not isomorphous. The paper concludes with a discussion of the figure of merit FN for pseudosymmetric structures. It is suggested that two figures of merit be reported. The first should be the standard one using either all measured reflections or just the first 30. The proposed second figure of merit does not include any superlattice reflections. These superlattice reflections tend to be very weak, resulting in a low completeness factor and relatively large error in the measurement of their position. This effect produces an unrealistically low value of the standard figure of merit. By including only “main” reflections, i.e., those reflections that are common to both the low-symmetry and high-symmetry parent phase (if it exists), a much better estimate of the quality of the fitting of the measured diffraction pattern is obtained.
An introduction of chemical structure coding in the X-ray Powder Diffraction File
Authors: Lianhu Wei , Yunde Xiao , Jinbei Zhang , ShaoFan Lin
Published: January 2013

A special computer storage method for chemical structures is illustrated in this article. With an improved method of two-dimensional connection table and topology, we can fit almost all chemical structures and display them very conveniently. We have used this method in the PDF (X-Ray Powder Diffraction File) database, which contains many special structures.

Key words: database, computer application, chemical structure
A synchrotron study of bladder urolith architecture
Authors: Rogers K. D. , Sperrin M. W. , MacLean E. J.
Published: January 2013

The principal aim of this study was to assess a new approach to the characterization of uroliths using synchrotron radiation. To achieve this, a detailed investigation of the crystalline nature of a human bladder urolith has been undertaken. Changes in the phase composition and crystalline mineral nature have been measured from the urolith core center to its outer surface. Data were collected using a microbeam, synchrotron probe, and image plate. Rietveld analysis has enabled us to determine that the unit cell dimensions of the majority phases (anhydrous uric acid and calcium oxalate monohydrate) are significantly greater in the core region but become progressively smaller from the outer to inner regions. The crystallites of both phases are also shown to possess significant radial orientation which varies through the urolith and reaches a maximum at a point of principal fracture. The analysis has also allowed us to study the change in average crystallite morphology; the crystallites of both phases are shown to decrease in size toward the outer parts of the urolith although this is in a nonuniform fashion. Evidence of calcium oxalate dihydrate was also found, but only within the outermost region of the urolith.
X-ray powder diffraction data for calcium galactarate tetrahydrate CaC6H8O8·4H2O and Rietveld refinement of the crystal structure
Authors: Barbier B. , Euler H.
Published: January 2013

The powder pattern of calcium galactarate tetrahydrate (CaC6H8O8·4H2O) is presented. The compound was found in white wine stored for 4 years. A Rietveld refinement using the atomic coordinates from a single crystal study as starting values was refined with 55 parameters and without preferred orientation to RB=5.97%, RF=4.44%, Rp=10.39%, and Rwp=13.43% for 84 reflections. Crystal data: Mr=320.14, orthorhombic, Pcan, a=7.3359(1) Å, b=11.6296(3) Å, c=15.0978(6) Å, V=1288.05(6) Å3, Z=4, Dx=1.651 g/cm3, λ(CuKα1)=1.54060 Å, μ=46.76 cm−1.
The Value of X-ray Powder Diffraction Patterns, and the Structure of the Manganese-Aluminum Alloys with Apparent Icosahedral Symmetry
Authors: Pauling Linus
Published: January 2013

I have made use of X-ray powder diffraction patterns for over sixty years. In the summer of 1922, in anticipation of my becoming a graduate student in chemistry, I read the book “X-Rays and Crystal Structure,” by W. H. and W. L. Bragg. Then in September 1922 I arrived in Pasadena, and immediately began to learn how to determine the structure of a crystal by a study of the X-ray diffraction pattern from Roscoe Gilkey Dickinson, who was the first person to have received a Ph.D. degree from the California Institute of Technology (1920). The procedure in use in Pasadena started with the preparation of a photograph showing lines obtained by Bragg reflection from a developed face of a large crystal with monochromatic radiation, usually molybdenum K alpha and beta. Measurement of the angle of reflection gave a set of possible values for the length of the edges of the unit of structure, usually of a cubic, hexagonal, or tetragonal crystal, since the methods were not powerful enough to permit the evaluation of more than two or three parameters. The next step was the preparation of Laue photographs, and their analysis. This was a powerful method, which often led to the correct structures.
Computer Automation of Structure-Sensitive Search-Match Algorithm for Powder Diffraction Analysis
Authors: Filsinger D. H. , Frevel L. K.
Published: January 2013

The Semi-manual Structure-sensitive SEARCH-MATCH procedure [Frevel, (1982), Anal. Chem. 54, 691–697] has been automated for the Hewlett-Packard HP 3354 Computer. The software is coded in the interpretive HP LAB BASIC II language. A core file of 1026 selected powder diffraction standards has been compiled covering the common crystalline phases encountered in industry, the ubiquitous crystalline minerals, and prototypes of the more frequently found crystal structures. Solid solutions can be readily identified.
Chemical Analysis by X-Ray Diffraction: Classification and Use of X-Ray Diffraction Patterns
Authors: Hanawalt J. D. , Rinn H. W. , Frevel L. K.
Published: January 2013

Editor's Note: As part of our plan to reprint previously published papers of great historical interest, the editorial board is pleased to reproduce the following paper by Hanawalt, Frevel and Rinn. This paper was originally published in Volume 10 (1938) of the Analytical Ediction of “Industrial and Engineering Chemistry” and is considered by most diffractionists to be the classic work in qualitative identification of multiphase polycrystalline material. The original publication carried a foreword written by the editor of Industrial and Engineering Chemistry. This foreword ended with this prophetic statement:

“There is reason to believe that this publication, which is made possible in this form by the generous financial assistance of the Dow Chemical Company, will serve to bring this method of analysis into general use in industrial and consulting analytical laboratories.”
Powder Diffraction Data for Trans-Bis (Dimethylphenylphosphine) Bis (Pyrazole) Platinum, [Pt(C3H4N2)2{P(CH3)2(C6H5)}2] and Trans-(Tricyclohexylphosphino)-(Triethylphosphino) Platinum(II) Chloride, PtCl2P2C24H48
Authors: Mullica D. F. , Sappenfield E. L.
Published: January 2013

The indexed X-ray diffraction powder data of trans-bis(dimethylphenylphosphine)bis(pyrazole)platinum, {Pt(C3H4N2)2[P(CH3)2(C6H5)]2, PTPP} and trans-(tricyclohexylphosphino) (triethylphosphino) platinum(II) chloride, (PtCl2P2C24H48, PTHE) are reported. PTPP crystallizes in the monoclinic space group C2/c and PTHE crystallizes in the orthorhombic space group Pcab. The refined cell parameters were determined by employing a Siemens Debye-Scherrer camera (Fe radiation, λmean = 1.93736 Å). The cell constants are a = 21.516(5), b = 6.287(1), c = 17.929(4)Å, β = 102.51(1)°, V = 2367.7Å3 Dx=1.70Mg m−3, Dm = 1.70Mg m−3 for PTPP and a = 12.271(1), b = 19.375(1), c = 23.864(3)Å, V = 5673.4Å3, Dx = 1.553Mg m−3 for PTHE. The quantitative figures of merit (FN) are F23 = 47(0.010,51) [F20 = 60(0.009,35)] for PTPP and F30 = 12(0.008,324) [F20 = 27(0.017,105)] for PTHE. The JCPD S Diffraction File No. for PTPP is 37-1999 and for PTHE is 37-2000.
Powder Diffraction Data of Polymorphic Phases of Dicesium Cadmium Tetraiodide Cs2CdI4
Authors: Touchard V. , Louër M. , Louër D.
Published: January 2013

Introduction: Phase transition has been recently observed in Cs2CdI4 (Touchard, Louër, Auffrédic & Louër, 1986). Thermal analysis has shown that the transformation occurs at 122°C. By quenching, the high temperature phase (β) can be stabilized at room temperature. In the present work we report the X-ray diffraction powder data, at room temperature, for the two phases α- and β-Cs2CdI4. Both phases have been indexed automatically by using powder indexing methods.
Quantitative Analysis of Sedimentary Minerals by Powder X-ray Diffraction
Authors: Bayliss Peter
Published: January 2013

The variables of reflection overlap, crystallinity and crystallite size, primary extinction, microabsorption, chemical substitutions, preferred orientation, and analytical procedures affect quantitative analysis by powder X-ray diffraction. The intensity of the strongest reflection (I) of 39 minerals from a typical sedimentary environment divided by the intensity of the strongest reflection (Ic) of corundum, I/Ic, may be used to determine mineral percentages. Because of the numerous variables mentioned above, the I/Icratios used should be taken from multi-mineral specimens that occur either in the same geological formation for quantitative analysis (±7%) or in a similar geological formation for quantitative analysis (±30%).
Acquisition and Analysis of Powder X-Ray Diffraction Data Using CALS Chromatographic Software
Authors: Moynihan Kelly J. , Proulx Richard , Windsor Brian K.
Published: January 2013

A conventional semi-automated powder X-ray diffractometer that was previously equipped with a strip chart recorder for data acquisition has been interfaced to an HP 1000 minicomputer via an analog-to-digital converter. Data acquisition and analysis is now accomplished using CALS chromatographic software and two in-house-developed FORTRAN 77 computer programs. This has resulted in significant improvements in experimental repeatability and accuracy, decreased sample turn-around times, and rapid and facile analysis, manipulation, and comparison of crystallographic data.
Searching and Matching of X-Ray Powder Diffraction Patterns Using a Programmable Calculator
Authors: Škrobian Milan , Havlik Tomas , Havlik Milan
Published: January 2013

A simple, practical search/match program, RIFRAN 85, has been written and implemented for the EMG 666B programmable calculator. The computer programs are written in EMG Assembler, which is identical to the assembler language for the Hewlett-Packard 9821 calculator. The EMG 666B is made in Hungary and has 8 kbytes of operational memory. The programs interactively provide qualitative phase analysis of X-ray powder diffraction patterns using standard files collected from published data and stored on a compact magnetic tape cassette. Each standard pattern can comprise up to 35 two-theta — intensity pairs. The identification procedure is based on the comparison of the diffraction data of the standard and of the unknown within limits imposed by user-established match and chemical criteria. This paper describes the algorithm used and the performance of the RIFRAN 85 identification system. The system's operation is illustrated using an example of phase analysis of a mineral sample.
X-Ray Quantitative Analysis of Coal By The Reference Intensity Method
Authors: Davis Briant L. , Johnson L. Ronald , Mebrahtu T.
Published: January 2013

Twenty-four coal samples representing the four major rank types were analyzed by the X-ray RIM methodology which includes mass absorption analysis by X-ray transmission and quantitative X-ray powder diffraction. Twenty-three separate mineral species were observed in the samples, many of which could be quantified in the whole coal analysis. Several mineral species at levels of 5 weightpercent or less were observed only in the ashed scans. Some dehydration and reconstitution reactions were observed in the ashing process, including the combination of organically bound alkaline-earth elements and sulfur to form bassanite and magnesium sulfates. Quartz and kaolinite dominated the silicate mineral portion of the mineralogy, whereas calcite and siderite represented the carbonate; pyrite with associated sulfate oxidation products were generally present as well. The X-ray transmission studies were successful in estimating the carbonaceous matter in the whole coal samples and comparison of the chemical oxides derived from the X-ray data with direct analyses from the Penn State data sheets revealed good correlations, although significant departures occurred for some species and a systematic underestimation of aluminum oxide from the X-ray clay peaks was observed. This study suggests that the RIM procedure can be applied to coal mineral and amorphous component analysis on a routine basis.
New Copper (II) — Rare Earth (III) Compounds II. Crystal Chemistry of CuLn2Ge2O8, CuLn2Si4O12 and CuLn2Ge4O12
Authors: Lambert U. , Eysel W.
Published: January 2013

Twenty seven new rare earth (Ln) compounds CuLn2 Ge2O8, CuLn2Ge4O12 and CuLn2Si4O12 have been synthesized. The powder diagrams were indexed and solid solutions of silicates and germanates were investigated. Structural variations with temperature, lanthanide contraction and Ge/Si substitution are described. Indications for second order phase transitions were found.
Standard X-Ray Diffraction Powder Patterns from The JCPDS Research Associateship
Authors: McMurdie Howard F. , Morris Marlene C. , Evans Eloise H. , Paretzkin Boris , Wong-Ng Winnie , Hubbard Camden R.
Published: January 2013

The following new or updated patterns are submitted by the JCPDS Research Associateship at the National Bureau of Standards. The patterns are a continuation of the series of standard X-ray diffraction powder patterns published previously in the NBS Circular 539, the NBS Monograph 25, and in this journal. The methods of producing these reference patterns are described in this journal, Vol. 1, No. 1, p. 40 (1986).

The data for each phase apply to the specific sample described. A sample was mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2-theta values for these standards are specified in the methods described (ibid.). Data, from which the reported 2-theta values were determined, were measured with a computer controlled diffractometer. Computer programs were used to locate peak positions and calibrate the patterns as well as to perform variable indexing and least squares cell refinement.
Considerations in the Design of Goniometers for Use in X-Ray Powder Diffractometers
Authors: Jenkins R. , Schreiner W. N.
Published: January 2013

Most modern X-ray powder diffraction work is carried out using the parafocusing powder diffractometer. The typical instrument employs a mechanical goniometer to control the basic geometric movements required for recording diffraction data. Modern trends toward high speed data acquisition and computerized analytical procedures make the need for a well designed and well maintained goniometer system increasingly critical. This paper reviews the mechanical design parameters of typical goniometer systems in light of their influence on the accuracy and precision obtainable in diffraction data. Data on typical vertical and horizontal goniometer systems are compared, along with bench tests using a state of the art “anti-backlash” gearing system. By examining the nature of the errors typically encountered in today's goniometers it becomes evident why the next major improvement will likely be in software rather than hardware.
The Application of X-Ray Powder Diffraction to Forensic Science
Authors: Thatcher P. J. , Briner G. P.
Published: January 2013

Although forensic science is regarded with a certain amount of fascination and admiration by the general public, to the practising forensic scientist it is often associated with painstaking and frustrating examinations.

This is particularly so in the most traditional area of forensic science, namely that of contact evidence where the identification and comparison of minute samples may provide an important clue for the investigator and assist in the conviction or exoneration of an accused person.

Contact evidence may include hairs and other fibres, paint samples, glass fragments, stains, soils and other deposits. Modern instrumentation such as infra-red spectrophotometry, gas chromatography, atomic absorption spectroscopy and energy dispersive X-ray analysis now allows a relatively simple identification of the composition of these materials. However, these techniques are not necessarily directed towards the absolute determination of structure of materials and this is particularly so in the case of crystalline materials of forensic interest such as soil, mortar, brick dust and paint fillers. Although the techniques previously mentioned provide the basis of an elemental analysis this may not be of much assistance in a forensic approach where chemical structure is the basis of a scentific comparison.
X-Ray Diffractometry of Low-Mass Samples
Authors: Zevin L. S. , Zevin I. M.
Published: January 2013

The intensity diffracted by a low-mass sample with negligible absorption may be expressed as It = I∞ (B/2μ*)/G, where I∞ = intensity diffracted by a bulk sample, B = cross section of the primary beam, μ* = mass absorption coefficient, and G = mass of the sample. Measurable intensity may be obtained from samples with less than 1 μg mass. In order to improve the limit of detection, the primary beam should be collimated so as to irradiate the sample and only a minimum volume of the sample support. The optimum spreading area of a low-mass sample is S sinθ≅10μ*. Comminution of low-mass samples to 1 — 2μm particles is adequate for reasonable intensity measurements.
Quantitative Phase Analysis By Linear Regression of Chemistry on X-Ray Diffraction Intensity
Authors: Renault Jacques
Published: January 2013

XRF and XRD measurements made on a single pressed powder briquet can be combined to give more quantitative information than either technique employed alone. Speed of analysis and simplification of sample preparation are also enhanced. The algorithm presented here uses multiple linear regression of the concentrations of one or more elements on the corrected X-ray diffraction intensities of the phases containing them. The data reduction program runs on a microcomputer. Data are presented to show its application to mineralogical analysis of artificial mixtures of quartz, microcline (a feldspar) and calcite.
X-Ray Powder Structural Analysis of the Complexes of Benzo-15-Crown-5 with NaClO4 and KI: [C14H20O5]NaClO4 and [C14H20O5]2KI
Authors: Shoham G. , Cohen N. , Schneider S. , Mayer I.
Published: January 2013

X-ray powder diffraction analysis of the complex of Benzo-15-Crown-5 (B-15-Crown-5) with NaClO4 displays a monoclinic crystal system with refined unit cell parameters of a = 8.829(3)Å, b = 8.327(3)Å, c = 24.21(2)Å, ß = 99.18(1)Å, V = 1757.1(1)Å3, Z = 4, and Dx = 1.48 g/cm3. The space group, P21/c, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of the powder analysis. X-ray powder diffraction analysis of the complex of B-15-Crown-5 with KI displays a tetragonal crystal system with refined unit cell dimensions of a = b = 17.869(3)Å, c = 9.761(3)Å, V = 3116.7(1)Å3, Z = 4, and Dx = 1.50 g/cm3. The space group, P4/n, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of die powder diffraction analysis. The powder and single crystal analyses of the two complexes indicate that in the solid phase, B-15-Crown-5 forms a 1:1 complex with Na+ and a 2:1 complex with K+. The variation in the complexation mode of B-15-Crown-5 with different cations, partially explains the lack of selectivity of this crown ether towards Na+, while from considerations of the cavity size alone this crown ether was expected to be considerably selective towards this cation.
Standard X-Ray Diffraction Powder Patterns of Fifteen Ceramic Phases
Authors: Wong-Ng Winnie , McMurdie Howard F. , Paretzkin Boris , Hubbard Camden R. , Dragoo Alan L. , Stewart James M.
Published: January 2013

The following fifteen reference patterns of boride, silicide and oxide ceramics represent the first group of ceramic phases measured at the National Bureau of Standards under the project “High Quality Reference Patterns and Total Digital Powder Patterns of Technologically Important Ceramic Phases”. The support and interest of the JCPDS-ICDD in this project is gratefully acknowledged.

The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40(1986).
Powder X-Ray Data for Synthetic Anhydrous Sodium Zirconium Silicates
Authors: Wilson G. , Glasser F. P.
Published: January 2013

A systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.
X-Ray Powder Diffraction and Single-Crystal Data for the Isomorphous Series (Fe,Al)3(K,NH4, H3O)H14(PO4)8 ·4H2O
Authors: Waerstad Kjell R. , Frazier A. William
Published: January 2013

X-ray powder diffraction and single-crystal data are reported for a series of isomorphous compounds with the general chemical composition (Fe,Al)3(K,NH4,H3O)H14 (PO4)8·4H2O. The compounds are monoclinic with space group C2/c. Unit-cell parameters were determined on the mixed salt (Fe0.84,Al0.16)3KH14(PO4)8·4H2O, as obtained from sludge precipitated in commercial shipping-grade wet-process phosphoric acid. Single-crystal studies and refined powder diffraction data provided unit-cell parameters of a= 16.908(9) Å, b = 9.588(2) Å, c = 17.539(5) Å, and β = 91.06(4)°.
Determination of Mica Cell Parameters by X-Ray Powder Diffractometry — A Case Study
Authors: Stern W. B.
Published: January 2013

Possibilities and restrictions of least-square methods for mica cell refinement are briefly described. If diffractometric raw data are precise and accurate, and if geometrical errors are properly corrected, a cell refinement (determination of ao, bo, cO, β) can be carried out rapidly, but the reliability of obtained data has to be evaluated carefully.
Application of the Rietveld Refinement Procedure in Assaying Powdered Mixtures
Authors: O'Connor Brian H. , Raven Mark D.
Published: January 2013

Results are given of an assessment of a Rietveld-type X-ray powder diffraction pattern fitting structure refinement technique for assaying powdered mixtures as an alternative to conventional discrete peak empirical methods of the type described by Klug and Alexander (1974) and Chung (1974). The values obtained for a mixture of corundum and α-quartz, following calibration of the instrument with a profile of the former, indicate that this technique has excellent potential as an analytical tool.
Bragg-Brentano and Seeman-Bohlin Diffractometers for Thin Films
Authors: Zevin L. S.
Published: January 2013

The performances of Seeman-Bohlin (S-B) and Bragg-Brentano (B-B) diffractometers with flat thin film samples were compared on the basis of equal instrumental aberrations. It was found that the S-B arrangement has only a marginal advantage as regards diffracted intensity, and that both types of diffractometer may be successfully employed for characterization of thin films. Diffraction data obtained with very thin metallic films (down to 30 Å) are included for illustration. In order to eliminate reflections from the singlecrystal substrate in the B-B diffractometer, sample tilting was employed. Provided the tilting angle remains within 0.5°, sample tilting causes only moderate additional broadening of the thin film peaks.
Laboratory Note. A LOTUS 1-2-3 Spreadsheet to Aid in Data Reduction for Publication of X-Ray Powder Diffraction Data
Authors: McCarthy Gregory J.
Published: January 2013

My students and I have developed a LOTUS 1-2-3 spreadsheet to aid in data reduction tasks associated with preparing powder diffraction data for publication in the Powder Diffraction File (PDF) (1987) and this journal. Portions of a sample spreadsheet and the formulae in each of the computational cells are given in the Table 1. The concept of this spreadsheet should apply to any of the available computer spreadsheet programs, although the specific codes for the mathematical functions may differ.

The user enters data only into columns C, D and F-H. All other entries will be calculated from the input data. Observed 2θ angles are entered into column D. The corresponding d-spacing is calculated in column A. The Miller indices of these peaks are entered into column C. Prior to use of the spreadsheet, the observed 2θ angles and hkl's had been used to refine unit cell parameters using the Appleman and Evans (1973) least squares unit cell parameter refinement computer program implemented for the IBM PC by Garvey (1986).
Données Cristallographiques sur le Trioxalato-Chromate (III) de Rubidium Trihydrate: Rb3(Cr(C2O4)3), 3H2O
Authors: Merrachi E.H. , Chassagneux F. , Mentzen B.F.
Published: January 2013

The trihydrated rubidium trioxalato-chromate(III), Rb3(Cr(C2O4)3)·3H2O cristallizes in the monoclinic system with:

The space group is P21/c. CuKα wavelength 1.541778.
An Inexpensive Automation of a Powder Diffractometer
Authors: Madsen J.C. , Skov H.J. , Rasmussen S.E.
Published: January 2013

A conventional Bragg-Brentano type diffractometer was equipped with a stepping motor, a timer, and a scaler, and an MC68000 Motorola microprocessor which controls the diffractometer functions. The microprocessor was programmed to operate the diffractometer in a step-scanning mode, to check a datum and to communicate with a process control computer, e.g. a PDP 11/44 or a Micro VaxII computer.
The X-Ray Crystallography of Tavorite from the Tip Top Pegmatite, Custer, South Dakota
Authors: Roberts Andrew C. , Dunn Pete J. , Grice Joel D. , Newbury Dale E. , Roberts Willard L.
Published: January 2013

Bright apple green millimeter-sized crystals of tavorite from the Tip Top pegmatite, near Custer, South Dakota are triclinic, space group , with refined unit-cell parameters a = 5.340(2), b = 7.283(2), c = 5.110(2)Å, α = 109.29(2)°, β = 97.86(3)°, γ = 106.32(3)°, V = 174.1(3)Å3, a:b:c = 0.7332:1:0.7016, Z = 2, D(m) (suspension in methylene iodide) = 3.32(1) and D(x) = 3.33 g/cm3 (for the theoretical formula). A fully indexed X-ray powder pattern is presented. Semiquantitative electron microprobe and secondary ion mass spectroscopic analyses indicate a formula near end-member LiFe + 3(PO4)(OH). The Tip Top tavorite is biaxial positive, α = 1.795(5), β = 1.81(1), γ = 1.86(1), 2V(meas.) = 50(2)°, 2V(calc.) = 59°, XΛa ≃ 15°, YΛb ≃ 0°, and ZΛc ≃ 38°. There is no evidence for optical absorption, pleochroism or dispersion.
X-Ray Powder Data for Acetaminophen (C8H9NO2)
Authors: Welton Jean M. , McCarthy Gregory J.
Published: January 2013

X-ray powder data and crystal data for acetaminophen, C8H9NO2, are reported and results are compared to existing PDF patterns.
Tables of Experimental Reference Intensity Ratios
Authors: Davis Briant L. , Smith Deane K.
Published: January 2013

This paper presents the first Table of RIR values for quantitative analysis as a model for regular updates which will appear in future issues. Diffractionists interested in the reference intensity method of quantitative analysis are urged to read the criteria for preparing data to continue this Table and then to submit new data.
Establishing an Instrumental Peak Profile Calibration Standard for Powder Diffraction Analyses: International Round Robin Conducted by the JCPDS-ICDD and the U.S. National Bureau of Standards
Authors: Fawcett T. G. , Crowder C. E. , Brownell S. J. , Zhang Y. , Hubbard C. , Schreiner W. , Hamill G. P. , Huang T. C. , Sabino E. , Langford J. I. , Hamilton R. , Louër D.
Published: January 2013

With the explosive growth in the number of highly automated powder diffraction systems, many types of analyses which were previously considered a specialty analysis are now performed on a routine basis. Algorithms have been developed for measuring peak profiles from which crystallite sizes, residual microstrain, and X-ray crystal structure (Rietveld techniques for example) can be determined. However, these techniques require an instrumental peak profile calibration standard to correct the experimental data for instrumental broadening due to the system optics.

Significant problems are encountered when laboratories try to cross-correlate or reproduce published data due to the lack of a common reference material for instrumental calibration. This is particularly distressing in microstrain and crystallite size calculations which can be dramatically affected by a poor choice of standard materials. Microstrain and crystallite size measurement are becoming increasingly important for the characterization of advanced materials and catalysts.
Crystal Data for p-Dibromobenzene/p-Chloroiodobenzene “Molecular Alloys”
Authors: Calvet T. , Tauler E. , Cuevas-Diarte M.A. , Estop E. , Alcobé X. , Labrador M. , Haget Y.
Published: January 2013

Crystal data for four p-dibromobenzene/p-chloroiodobenzene mixed crystals, (pDBB)x(pCIB)1-x, with x = 0.1, 0.4, 0.7, 0.9, synthesized by the fusion-quenching method, and a typical powder diffraction pattern are reported. The unit cell is monoclinic with S.G. = P21/a and Z = 2. Cell parameters of solid solution members varied almost linearly between the end member values.
Laboratory Note. Obtaining Powders with the Aid of a Slow Speed Diamond Saw
Authors: Kayser F.X.
Published: January 2013

Powder samples for diffraction studies of selected materials have been prepared in this laboratory during the past 15 years using a commercial, slow-speed, diamond saw. The materials powdered include a wide range of ferrous and transition metal alloys as well as geological substances. Before sectioning begins, fresh oil is poured into the oil tray of the saw and the diamond, rim-impregnated, copper blade thoroughly cleaned. A typical blade is 10 cm in diameter and 3 mm thick. Powder produced as the blade cuts through the sample collects in and settles to the bottom of the oil tray. The oil, which bathes the sample surface during cutting and surrounds the powder debris after discharge into the tray, serves to prevent oxidation of most materials.
Tables of Experimental Reference Intensity Ratios Table No. 2, December, 1989
Authors: Davis Briant L. , Smith Deane K. , Holomany Mark A.
Published: January 2013

This is a second and considerably expanded edition of the RIR table. We are pleased that considerable interest is now being generated in the RIR table; several contributors have provided measured data for this second edition. We have also added many entries of common minerals and simple compounds from the JCPDS data base and will continue to add more from this source with each succeeding table published. In this regard where we receive requests for a particular class of RIR's (alloys, or rare earth oxides, for examples) we can give higher priority to extracting these values from the JCPDS data base.

The reader should refer to the text explanation of the first published table in Vol. 3, No. 4 of this journal. In the first text two important errors are noted here; Equation (3) should have read RIRcorr = RIRobs/Wj; and the second sample preparation category of section 4 Specific Parameters should read “(w) Methods including well mounts with side or back loading or similar process”.
Exhaustive indexing of triclinic powder diffraction patterns with known unit cell parameters
Authors: Frevel Ludo K.
Published: January 2013

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.
X-ray powder diffraction data for five lanthanoid chromates [Ln2(CrO4)3(H2O)5]·2H2O (Ln=La,Pr,Nd,Sm,Eu)
Authors: Leppä-aho Jaakko , Valkonen Jussi
Published: January 2013

X-ray powder diffraction data are reported for a series of isomorphous compounds of [Ln2(CrO4)3(H2O)5]·2H2O, where Ln=La, Pr, Nd, Sm, or Eu. The compounds crystallize in monoclinic space group P21/c (No: 14) with Z=4. Refined unit cell parameters and indexed powder diffraction patterns are given.
Crystal data of two thiophosphates ATi2(PS4)3 with a new structural type (A=Na, Ag)
Authors: Cieren X. , Angenault J. , Couturier J-C. , Quartern M.
Published: January 2013

Two new thiophosphates with an original structure corresponding to formula ATi2(PS4)3 (with A=Na,Ag) were synthesized by solid-state reaction. The two compounds are isostructural, hexagonal space group P6cc, Z=8. A single crystal of NaTi2(PS4)3 has been studied. Unit-cell parameters were determined for NaTi2(PS4)3 and AgTi2(PS4)3, respectively: a= 19.9131(6) Å, c= 11.5542(7) Å, V=3967.8(3) Å3 and a=20.0146(8) Å, c= 11.5467(8) Å, V=4005.7(4) Å3. Powder diffraction data are reported.
X-ray powder diffraction data for CuFeSe2
Authors: Henaoa J. A. , Delgado J. M. , Quintero M.
Published: January 2013

Recent X-ray single-crystal diffraction studies have shown that CuFeSe2 crystallizes in the tetragonal system with space group P2c [, No. 112], Z = 4, with a =5.530(1) Å and c = 11.049(2) Å, c/a = 1.998. This material had been reported as pseudocubic with a =5.53 Å. The purpose of this paper is to present new X-ray powder diffraction data for CuFeSe2 and to compare the results with those reported for eskebornite, a mineral with ideal chemical composition CuFeSe2, and with those obtained from single-crystal structure data.
A monotitanate with a stuffed cristobalite structure type
Authors: Colbeau-Justin C. , Elfakir A. , Quarton M.
Published: January 2013

A new titanate K2ZnTiO4 has been synthesized by solid-state reaction. This compound is isostructural with K2ZnGeO4, space group Pca21, Z=8. Unit-cell parameters were determined: a=11.3352(6) Å, b=5.6352(5) Å, c=16.0125(13) Å, and V=1022.8(3) Å3. Powder diffraction data are reported.
Incommensurately modulated structure of Bi2Sr2Eu1.3Ce0.7Cu2O10.17 refined from X-ray powder data
Authors: Khasanova N. R. , Mironov A. V. , Antipov E. V.
Published: January 2013

The incommensurately modulated structure of Bi2Sr2Eu1.3Ce0.7Cu2O10.17, with a = 5.4752(4) Å, b = 5.4522(3) Å, c = 17.860(1) Å, Z = 2, was refined by the GJANA program [Gao et al., Acta Cryst. A 49, 141 (1993)] from X-ray powder data in C:C2mb: 111 four-dimensional space group (Rov = 0.064, Rm = 0.041, Rsat = 0.202, Rp = 0.049, Rwp = 0.065). Displacive modulation parameters of all cations and oxygen atoms in the Bi-layer were involved in the refinement. Obtained results including the modulation parameters are in agreement with those found for the similar phase Bi2Sr1.7Nd1.8Ce0.5Cu2O10+δ from single-crystal data [Mironov et al., J. Solid State Chem. 109, 74 (1994)].
The automation of DRON diffractometers
Authors: Stepanov V. , Bondars B.
Published: January 2013

A resident powder diffractometer control program is described, which allows independent use of the PC for other programs during data collection. The control program and a simple interface card were developed for the case when a PC is used to automate the DRON type diffractometers.
Test of maximum-entropy methods to solve a small structure ab initio from powder diffraction data
Authors: Sudo Naoaki , Hashizume Hiroo , Carvalho Carlos A. M.
Published: January 2013

Detailed procedures for solving small crystal structures ab initio with the maximum-entropy (ME) methods using X-ray powder diffraction data are described by determining the structure of the low-pressure phase of magnesium boron nitride, Mg3BN3(L), which was previously solved by one of the authors and co-workers using the Patterson method and the direct methods. The simple ME method devised by Gull, Livesey, and Sivia failed to correctly phase the structure-factor data, leading to noninterpretable electron-density maps. This method, maximizing the entropy under the constraints of the observed structure factors with subsequent incorporation of strong extrapolates in the basis set, trapped the solution in a local entropy maximum, from which there is no way to move. The multisolution method of phase determination by entropy maximization and likelihood evaluation, developed by Bricogne and Gilmore, successfully located all the Mg, B, and N atoms in one cycle of phase extension. The correct solution had a highest log-likelihood gain, but a minimum entropy, among the multisolutions generated by phase permutation.
Quantitative mineraiogical analyses of carbonate rich sediments by X-ray powder diffraction
Authors: Mansour A. M. , Piller W. E. , Lengauer C. L.
Published: January 2013

The quantitative analysis of carbonate rich materials is tested with conventional and Rietveld methods. In the case of artificial mixtures of aragonite, calcite, Mg-calcite and quartz the Rietveld method provides reliable results with a maximum deviation of ±5 wt %. In the natural samples, however, the conventional methods give more reliable results in comparison to chemical and sedimentological measurements. This is caused by the peak overlap of calcite/Mg-calcite, peak roadening of the Mg-calcite, and the difficulties in the refinement of minor amounts of feldspar phases.
Ab initio structure determination and Rietveld refinement of the crystal structure of (Pb0.6Cu0.4)Sr2PrCu207−x
Authors: Yang Ping , Sivakumar K. , Fun Hoong-Kun , Lee Tsong-Jen , Ku Huan-Chiu , Lai Chiou-Chu
Published: January 2013

Ab initio structure determination of new compound (Pb0.6Cu0.4)Sr2PrCu2O7−x was obtained at 300 and 100 K from X-ray powder diffraction data and refined by Rietveld technique. (Pb0.6Cu0.4)Sr2PrCu2O7−x has an isotypical structure with TlBa2CaCu2O7 (1212) at both 300 and 100 K. At 300 K, crystal data: (Pb0.522Cu0.4)Sr2PrCu206.53, Mr=681.293, tetragonal system, space group P4/lmmm, a = 3.8631(5)Å, c= 11.9134(2)Å, V= 177.79Å3, Z= 1, Dx, = 6.3631 g/cm3, μ=1036.549 cm−1 (λ=1.54051 Å), F(000) = 299.6, the structure was refined with 31 parameters to Rwp = 4.02%, Rp=2.96% for 3379 step intensities and Rb = 4.80%, Rf=5.17 for 143 reflections, “goodness of fit” S = 2.20. At 100 K, crystal data: (Pb0.547Cu0.4)Sr2PrCu2O6.89, Mr=692.232, tetragonal system, space group P4/mmm, a = 3.8580(2) Å, c= 11.8898(5) Å, Z=1, Dx = 6.4953 g/cm3, μ= 1053.235 cm−1 (λ=1.54051 Å), F(000) = 304.6, the structure was refined with 32 parameters to Rwp = 5.53%, Rp=4.22% for 2574 step intensities and Rb = 6.11%, Rf=5.31% for 111 reflection, “goodness of fit” S= 1.79. Moreover, the composition of Pb was refined to 0.522 at 300 K and to 0.547 at 100 K as compared with the stoichiometric composition 0.6.
Small-angle scattering of X-rays in a conventional Bragg–Brentano diffractometer for quantitative analysis
Authors: Battaglia Stefano
Published: January 2013

A technique is presented utilizing an unmodified commercial X-ray diffractometer, equipped with a Bragg–Brentano geometry, for reducing preferred orientation effects in measured intensities during quantitative diffraction analysis. The diffractometer setup examined makes possible data acquisition with Θ fixed at 1° and 2Θ scanning the Bragg line. The results obtained with this technique are shown in the quantitative X-ray diffraction analysis of three international standards of carbonate rocks (401,402,403).
Powder X-ray data for the ammonium trioxalatoaluminate (III) and its hydrates: (NH4Al(C2O4)3·xH2O, x=0,2,3
Authors: Ezahri Mohamed , Coffy Georges , Mentzen Bernard F.
Published: January 2013

X-ray powder diffraction data are reported for the trihydrated (A3N), the dihydrated (A2N), and the anhydrous ammonium trioxalatoaluminate (III) (AN). A3N is triclinic with space group . A2N and AN are monoclinic with space groups P21/c and P21/n respectively. The stability domains are A3N: –7.8 to 86 °C; A2N: 86 to 102 °C; AN: 102 to 180 °C.
Powder diffraction analysis of an interstratified marcasite/pyrite structure
Authors: Johnson Neil E. , Pollack Sidney S. , Frommell Elizabeth A. , Eldredge Patricia A.
Published: January 2013

A synthetic catalyst precursor formed by sulfiding ferrihydrite (Fe3+O(OH)) in the presence of a hydrogen donor produces X-ray diffraction patterns resembling a mixture of both naturally occurring FeS2 polymorphs marcasite and pyrite. The diffraction peaks display a differential broadening, however, wherein only those peaks coincident to both marcasite and pyrite are strong and sharp, a feature that cannot be accounted for by a simple physical mixture. The broadening is analogous to that found in hexagonal cobalt, where occasional stacking faults produce interstratification of the hexagonal and cubic close-packed forms, resulting in strongly coherent diffraction only along the stacking direction. The crystal structures of marcasite and pyrite are virtually identical if viewed perpendicular to the (101) and (001) planes, respectively. Calculation of diffraction patterns based upon models of interstratifying marcasite and pyrite layers along these planes demonstrates that a sequence with marcasite-to-pyrite and pyrite-to-marcasite stacking fault probabilities of 0.22 provides a good fit to the experimental pattern. This interstratified material is a precursor to a species that shows catalytic activity for cleaving C-C bonds between aromatic rings and benzylic carbon atoms at low (<350 °C) temperatures.
X-ray powder diffraction analysis of a nonlinear optical material 4-chlorocinnamylidenyl-4′ -phenylacetophenone
Authors: Jin Zong-ming , Zheng Jin , Ai-hua Yuan
Published: January 2013

A nonlinear optical material, 4-chlorocinnamylidenyl-4′ -phenylacetophenone (C23H17ClO), 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 94 observed reflections with 2θ up to 60° are reported. The powder diffraction data have been evaluated, and the figures-of-merit are reported. The unit cell parameters least-squares refined from 30 nonoverlapping peaks of the orthorhombic compound with a P21212 space group are a =14.756(3) Å, b = 20.647(8) Å, c = 5.840(1) Å, V = 1779.3(9) Å3, Z = 4, and Dx = 1.287 g/cm3.