Crystal structure refinement of magnesium zinc divanadate, MgZnV2O7, from powder X-ray diffraction data

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.

Download Full-text

Crystal structure of calcium perchlorate anhydrate, Ca(ClO4)2, from laboratory powder X-ray diffraction data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989018003936 ◽

2018 ◽

Vol 74 (4) ◽

pp. 514-517 ◽

Cited By ~ 2

Author(s):

Dongmin Lee ◽

Hyeri Bu ◽

Dohwan Kim ◽

Jooeun Hyoung ◽

Seung-Tae Hong

Keyword(s):

Crystal Structure ◽

Powder Diffraction ◽

Diffraction Data ◽

Powder Diffraction Data ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

X Ray ◽

Wyckoff Position ◽

Hydrated Calcium

The crystal structure of calcium perchlorate anhydrate was determined from laboratory X-ray powder diffraction data. The title compound was obtained by heating hydrated calcium perchlorate [Ca(ClO4)2·xH2O] at 623 K in air for 12 h. It crystallizes in the orthorhombic space group Pbca and is isotypic with Ca(AlD4)2. The asymmetric unit contains one Ca, two Cl and eight O sites, all on general sites (Wyckoff position 8c). The crystal structure consists of isolated ClO4 − tetrahedra and Ca2+ cations. The Ca2+ cation is coordinated by eight O atoms of eight symmetry-related ClO4 − tetrahedra within a distorted square-antiprismatic environment.

Download Full-text

Crystal structure of strontium perchlorate anhydrate, Sr(ClO4)2, from laboratory powder X-ray diffraction data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989019003335 ◽

2019 ◽

Vol 75 (4) ◽

pp. 447-450

Author(s):

Jooeun Hyoung ◽

Hyeon Woo Lee ◽

So Jin Kim ◽

Hong Rim Shin ◽

Seung-Tae Hong

Keyword(s):

Crystal Structure ◽

Diffraction Data ◽

Bond Valence ◽

Structure Model ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

Space Group ◽

X Ray ◽

Wyckoff Position

The crystal structure of strontium perchlorate anhydrate, Sr(ClO4)2, was determined and refined from laboratory powder X-ray diffraction data. The material was obtained by dehydration of Sr(ClO4)2·3H2O at 523 K for two weeks. It crystallizes in the orthorhombic space group Pbca and is isotypic with Ca(AlD4)2 and Ca(ClO4)2. The asymmetric unit contains one Sr, two Cl and eight O sites, all on general positions (Wyckoff position 8c). The crystal structure consists of Sr2+ cations and isolated ClO4 − tetrahedra. The Sr2+ cation is coordinated by eight O atoms from eight ClO4 − tetrahedra. The validity of the crystal structure model for Sr(ClO4)2 anhydrate was confirmed by the bond valence method.

Download Full-text

Redetermination of Sr2PdO3 from single-crystal X-ray data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989018017176 ◽

2019 ◽

Vol 75 (1) ◽

pp. 30-32

Author(s):

Gohil S. Thakur ◽

Hans Reuter ◽

Claudia Felser ◽

Martin Jansen

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Diffraction Data ◽

Structure Refinement ◽

Structure Type ◽

X Ray Diffraction ◽

High Quality ◽

X Ray ◽

Cell Parameters ◽

Anisotropic Displacement Parameters

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.

Download Full-text

Ideal and Real Structure of Ti5O4(PO4)4: X-ray and HRTEM Investigations

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768198003590 ◽

1998 ◽

Vol 54 (6) ◽

pp. 722-731 ◽

Cited By ~ 17

Author(s):

F. Reinauer ◽

R. Glaum

Keyword(s):

Crystal Structure ◽

Electron Microscopy ◽

Structure Refinement ◽

Ideal Structure ◽

Crystal Data ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

The Ideal

The crystal structure of pentatitanium tetraoxide tetrakis(phosphate), Ti5O4(PO4)4, has been determined and refined from X-ray diffraction single-crystal data [P212121 (No. 19), Z = 4, a = 12.8417 (12), b = 14.4195 (13), c = 7.4622 (9) Å (from Guinier photographs); conventional residual R 1 = 0.042 for 2556 Fo > 4σ(Fo ), R 1 = 0.057 for all 3276 independent reflections; 282 parameters; 29 atoms in the asymmetric unit of the ideal structure]. The structure is closely related to those of β-Fe2O(PO4)-type phosphates and synthetic lipscombite, Fe3(PO4)4(OH). While these consist of infinite chains of face-sharing MO6 octahedra, in pentatitanium tetraoxide tetrakis(phosphate) only five-eighths of the octahedral voids are occupied according to □3Ti5O4(PO4)4. Four of the five independent Ti4+O6 show high radial distortion [1.72 ≤ d(Ti−O) ≤ 2.39 Å] and a typical 1 + 4 + 1 distance distribution. The fifth Ti4+O6 is an almost regular octahedron [1.91 ≤ d(Ti−O) ≤ 1.98 Å]. Partial disorder of Ti4+ over the available octahedral voids is revealed by the X-ray structure refinement. High-resolution transmission electron microscopy (HRTEM) investigations confirm this result.

Download Full-text

Al analogue of chayesite from a lamproite of Cancarix, SE Spain, and its crystal structure

Neues Jahrbuch für Mineralogie - Abhandlungen Journal of Mineralogy and Geochemistry ◽

10.1127/njma/2020/0193 ◽

2020 ◽

Vol 196 (3) ◽

pp. 193-198

Author(s):

Natalia V. Zubkova ◽

Nikita V. Chukanov ◽

Christof Schäfer ◽

Konstantin V. Van ◽

Igor V. Pekov ◽

...

Keyword(s):

Crystal Structure ◽

Diffraction Data ◽

Empirical Formula ◽

Structure Refinement ◽

Crystal Chemical ◽

Chemical Formula ◽

Crystal Chemical Formula ◽

X Ray Diffraction ◽

Se Spain ◽

X Ray

Al analogue of chayesite (with Al > Fe3+) was found in a lamproite from Cancarix, SE Spain. The mineral forms green thick-tabular crystals up to 0.4 mm across in cavities. The empirical formula derived from EMP measurements and calculated on the basis of 17 Mg + Fe + Al + Si apfu is (K0.75 Na0.20 Ca0.11)Mg3.04 Fe0.99 Al1.18 Si11.80 O30. The crystal structure was determined from single crystal X-ray diffraction data ( R = 2.38%). The mineral is hexagonal, space group P 6/ mcc, a = 10.09199(12), c = 14.35079(19) Å, V = 1265.78(3) Å3, Z = 2. Fe is predominantly divalent. Al is mainly distributed between the octahedral A site and the tetrahedral T 2 site. The crystal chemical formula derived from the structure refinement is C (K0.73 Na0.16 Ca0.11)B (Na0.02)4 A(Mg0.42 Al0.29 Fe0.29)2 T 2(Mg0.71 Fe0.16 Al0.13)3 T 1(Si0.985 Al0.015)12 O30.

Download Full-text

Crystal structure of cis-Tetracarbonylbis(chloromercury)iron

Australian Journal of Chemistry ◽

10.1071/ch9761905 ◽

1976 ◽

Vol 29 (9) ◽

pp. 1905 ◽

Cited By ~ 10

Author(s):

CL Raston ◽

AH White ◽

SB Wild

Keyword(s):

Crystal Structure ◽

Least Squares ◽

Diffraction Data ◽

Title Compound ◽

Direct Methods ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

X Ray ◽

Independent Molecules

The crystal structure of the title compound has been determined by direct methods from X-ray diffraction data and refined by least squares to a residual of 0.071 for 2647 'observed' reflections. Crystals are monoclinic, C2/c, a = 36.81(1), b = 11.181(2), c = 20.369(5) �, β = 95.28(3)�, Z = 32. There are four independent molecules in the asymmetric unit, all with the cis disposition of ligands (<Fe-Hg), 2.498 �; <Hg-Fe-Hg), 80.9�); in one of the molecules one of the carbonyl sites is occupied by a more substantial moiety, possibly a result of partial occupancy of HgCl as a result of disorder or decomposition.

Download Full-text

Diterbium heptanickel: a crystal structure redetermination

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536814015384 ◽

2014 ◽

Vol 70 (8) ◽

pp. i42-i42

Author(s):

Volodymyr Levytskyy ◽

Volodymyr Babizhetskyy ◽

Bohdan Kotur ◽

Volodymyr Smetana

Keyword(s):

Crystal Structure ◽

Diffraction Data ◽

Title Compound ◽

Stoichiometric Composition ◽

Structure Type ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Coordination Polyhedra ◽

X Ray ◽

Anisotropic Displacement Parameters

The crystal structure of the title compound, Tb2Ni7, was redetermined from single-crystal X-ray diffraction data. In comparison with previous studies based on powder X-ray diffraction data [Lemaireet al.(1967).C. R. Acad. Sci. Ser. B,265, 1280–1282; Lemaire & Paccard (1969).Bull. Soc. Fr. Mineral. Cristallogr.92, 9–16; Buschow & van der Goot (1970).J. Less-Common Met.22, 419–428], the present redetermination affords refined coordinates and anisotropic displacement parameters for all atoms. A partial occupation for one Tb atom results in the non-stoichiometric composition Tb1.962 (4)Ni7. The title compound adopts the Ce2Ni7structure type and can also be derived from the CaCu5structure type as an intergrowth structure. The asymmetric unit contains two Tb sites (both site symmetries 3m.) and five Ni sites (.m.,mm2, 3m., 3m., -3m.). The two different coordination polyhedra of Tb are a Frank–Kasper polyhedron formed by four Tb and 12 Ni atoms and a pseudo Frank–Kasper polyhedron formed by two Tb and 18 Ni atoms. The four different coordination polyhedra of Ni are Frank–Kasper icosahedra formed by five Tb and seven Ni atoms, four Tb and eight Ni atoms, three Tb and nine Ni atoms, and six Tb and six Ni atoms, respectively.

Download Full-text

Synthesis and Rietveld crystal structure refinement of mackinawite, tetragonal FeS

Mineralogical Magazine ◽

10.1180/minmag.1995.059.397.10 ◽

1995 ◽

Vol 59 (397) ◽

pp. 677-683 ◽

Cited By ~ 154

Author(s):

A. R. Lennie ◽

S. A. T. Redfern ◽

P. F. Schofield ◽

D. J. Vaughan

Keyword(s):

Crystal Structure ◽

Diffraction Data ◽

Structure Refinement ◽

X Rays ◽

Crystal Structure Refinement ◽

Powder Diffraction Data ◽

X Ray Diffraction ◽

Data Set ◽

X Ray ◽

Cell Parameters

AbstractMackinawite, tetragonal FeS, has been synthesised by reacting iron with Na2S solutions. A Rietveld structure refinement of X-ray powder diffraction data, recorded using X-rays monochromated from synchrotron radiation with a wavelength of 0.6023 Å, has been performed. The structure has been refined in the tetragonal space group, P4/nmm, and has the following cell parameters: a = 3.6735(4), c = 5.0328(7) Å, V = 67.914(24) Å3. Our refinement shows that the FeS4 tetrahedron in mackinawite is almost perfectly regular, with a much smaller distortion than has been previously reported. An improved X-ray diffraction data set is provided.

Download Full-text

Darstellung und Kristallstruktur von Zinkazid · 4-Methylpyridin / Preparation and Crystal Structure of Zinc Azide · 4-Methylpyridine

Zeitschrift für Naturforschung B ◽

10.1515/znb-1988-0302 ◽

1988 ◽

Vol 43 (3) ◽

pp. 253-256 ◽

Cited By ~ 8

Author(s):

Franz A. Mautner ◽

Harald Krischner ◽

Christoph Kratky

Keyword(s):

Crystal Structure ◽

Aqueous Solution ◽

Single Crystal ◽

Zinc Atom ◽

Monoclinic Space Group ◽

X Ray Diffraction ◽

Space Group ◽

X Ray ◽

Trigonal Bipyramidal ◽

Distorted Trigonal Bipyramidal

Zinc azide · 4-methylpyridine (1) is formed by the reaction of zinc azide with the corresponding pyridine in aqueous solution. The crystal structure was determined by single crystal X-ray diffraction methods. The crystals of 1 are monoclinic, space group C2/c, Z = 4, a = 1085.5(2), b = 1692.7(11), c = 619.7(6) pm, β = 113.47(5)°. Each zinc atom is surrounded by five nitrogen atoms (four from azide groups and one from the pyridine adduct) in a distorted trigonal bipyramidal fashion. The ZnN5-polyhedra share common edges to form chains along the crystallographic c-axis.

Download Full-text