Novel aluminophosphate Na6[Al3P5O20] with the original microporous crystal structure established in the study of a pseudomerohedric microtwin

2021 ◽  
Vol 77 (2) ◽  
pp. 232-240
Author(s):  
Olga V. Yakubovich ◽  
Galina V. Kiriukhina ◽  
Anatoliy S. Volkov ◽  
Olga V. Dimitrova ◽  
Elena Yu. Borovikova
Keyword(s):  
Crystal Structure ◽  
Unit Cell Parameters ◽  
Monoclinic Crystal ◽  
Cell Parameters ◽  
Monoclinic Crystal Structure ◽  
Generalized Framework ◽  
Microporous Zeolite ◽  
Phosphate Groups ◽  
Framework Density

The synthesis and characterization of a new aluminophosphate, Na6[Al3P5O20], obtained as single crystals in the same experiment together with Cl-sodalite, Na8[Al6Si6O24]Cl2, is reported. Na6[Al3P5O20], with a strongly pseudo-orthorhombic lattice, is described by the monoclinic crystal structure established in the study of a pseudomerohedric microtwin. The design of Na6[Al3P5O20] can be interpreted as an alternative to sodalite, with a monoclinic (pseudo-orthorhombic) 2×4×1 super-structure and unit-cell parameters multiples of those of sodalite: a ≃ 2a s, b ≃ 4b s and c ≃ c s. The triperiodic framework is built by AlO6, AlO4 and PO4 polyhedra having vertex-bridging contacts. While all the oxygen vertices of the Al-centred octahedra and tetrahedra are shared with phosphate groups, some of the PO4 tetrahedra remain `pendant', e.g. containing vertices not shared with other polyhedra of the aluminophosphate construction. Na atoms occupy framework channels and cavities surrounded by eight-, six- and four-membered windows with maximal effective pore widths of 4.86 × 3.24 and 4.31 × 3.18 Å. The generalized framework density is equal to 19.8, which means that the compound may be classified as a microporous zeolite. The Na6[Al3P5O20] crystal structure is discussed as being formed from octahedral rods arranged in two perpendicular directions, similar to the rods elongated in one direction in the NASICON-type compounds, which have been intensively investigated as promising materials for batteries. Analogous properties can be expected for phases with a modified composition of the Na6Al3P5O20 topology, where the Al atoms at the centres of octahedra are replaced by Fe, V or Cr.

scholarly journals STRUCTURAL CHARACTERIZATION OF THE NEW DIAMOND-LIKE SEMICONDUCTOR CuNbGaSe3

2018 ◽  
Vol 15 (29) ◽  
pp. 228-233
Author(s):  
J. A. FLORES-CRUZ ◽  
G. E. DELGADO ◽  
J. E. CONTRERAS ◽  
M. QUINTERO ◽  
L. NIEVES ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Behavior ◽  
Secondary Phase ◽  
Chalcopyrite Structure ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Chalcogenide Compound ◽  
Semiconductor Type

The chalcogenide compound CuNbGaSe3, belonging to the system I-II-III-VI3, has been investigated by means of X-ray powder diffraction and its crystal structure has been refined by the Rietveld method.This is a material of the semiconductor type, which improves the properties of a simple semiconductor like CuGaSe2 because it ads spintronic applications due to its magnetic behavior. The powder pattern was composed by 94.2% of the principal phase CuNbGaSe3 and 5.8% of the secondary phase Cu0.667NbSe2. This material crystallizes with a CuFeInSe3-type structure in the tetragonal space group P4 2c (Nº 112), unit cell parameters a = 5.6199(4) Å, c = 11.0275(2) Å, V = 348.28(4) Å3, with a normal adamantane-structure where occurs a degradation of symmetry from the chalcopyrite structure I4 2d to a related structure P4 2c.

Magnesio-riebeckite from the Varenche mine (Aosta Valley, Italy): crystal-chemical characterization of a grandfathered end-member

2017 ◽  
Vol 81 (6) ◽  
pp. 1431-1437 ◽  
Author(s):  
Roberta Oberti ◽  
Massimo Boiocchi ◽  
Frank C. Hawthorne ◽  
Marco E. Ciriotti
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Structure Refinement ◽  
Chemical Characterization ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
D Values

AbstractMagnesio-riebeckite from the dumps of the abandoned mine of Varenche (45°47’22’’ N, 7°29’17’’ E), Saint-Barthélemy, Nus, Aosta Valley (Italy), was studied to provide the complete mineral description (including crystal structure) and insights into the crystal-chemistry of riebeckite. The empirical formula derived from electron microprobe analysis and single-crystal structure refinement is A(Na0.09K0.01)Σ=0.10B(Na1.77Ca0.11Mg0.08Mn2+ 0:04)Σ=2.00C(Mg2.93Mn2+0:13Fe2+0:07Zn0.01Ni0.12Fe3+1:25Al0.48Ti0.01)Σ=5.00T(Si7.92Al0.08)Σ=8.00 O22W(OH1.88F0.12)Σ=2.00. Magnesio-riebeckite is biaxial (+), with α = 1.678(2), β = 1.682(2), γ = 1.688(2) and 2V (meas.) = 80.2(1.7)°, 2V (calc.) = 78.7°. The unit-cell parameters are a = 9.6481(14), b = 17.873(3), c = 5.3013(7) Å, β = 103.630(2)°, V = 888.4 (2)Å3, Z = 2, space group C2/m. The strongest ten reflections in the powder X-ray pattern [d values (in Å), I, (hkl)] are: 2.701, 100, (151); 8.303, 83, (110); 3.079, 62, (310); 3.391, 53, (131); 4.467, 50, (040,021); 2.522, 50, (̅202); 2.578, 35, (061); 2.155, 30, (261), 4.855, 30, (̅111), 2.300, 29, (̅351).

scholarly journals Synthesis, Characterization, and Crystal Structure of Negundoside (2′-p-Hydroxybenzoyl Mussaenosidic Acid)

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Suresh Sharma ◽  
B. D. Gupta ◽  
Rajni Kant ◽  
Vivek K. Gupta
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Direct Method ◽  
Monoclinic Crystal System ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Monoclinic Crystal ◽  
Full Matrix ◽  
X Ray ◽  
Cell Parameters

The structure of title compound Negundoside (2′-p-hydroxybenzoyl mussaenosidic acid) was established by spectral and X-ray diffraction studies. The compound crystallizes in the monoclinic crystal system with space group P21 having unit cell parameters: a=11.6201 (5) Å, b=9.2500 (4) Å, c=12.2516 (5) Å, β=97.793 (4)°, and Z=2. The crystal structure was solved by direct method using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R value of 0.0520 for 3389 observed reflections.

scholarly journals Structure and microstructure characterization of the La2SrB10O19 glass-ceramics

2019 ◽  
Vol 51 (4) ◽  
pp. 389-399
Author(s):  
Jovica Stojanovic ◽  
Sonja Smiljanic ◽  
Snezana Grujic ◽  
Predrag Vulic ◽  
Srdjan Matijasevic ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Borate Glass ◽  
Rietveld Method ◽  
Glass Ceramics ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure ◽  
Strontium Borate ◽  
Lanthanum Strontium ◽  
Structure And Microstructure

The crystal structure of new lanthanum strontium borate glass-ceramics was refined by the Rietveld method. The results showed that La2SrB10O19 has the monoclinic crystal structure, space group C2 (No. 5) with a = 11.1170(6), b = 6.5667(3), c = 9.2363(3) ?, ? = 91.481?, V = 674.04(7) ?3, two formula units per unit-cell, and density 3.830 g cm?3. The main building units of the crystal structure are BO4 tetrahedra and BO3 triangles. Clusters composed of [B5O12] form an infinite double layer running perpendicular to the c-axis. Lanthanum atoms, situated in [B5O12]n layers, are coordinated with 10 oxygen atom in a form of LaO10 polyhedra, while Sr atoms, located between [B5O12]n layers, are coordinated with 8 oxygen atoms in a form of SrO8 polyhedra. Microstructural measurements contain both crystallite domain sizes and microstrain calculations obtained by the Warren-Averbach and the simplified integral-breadth methods.

Twinning in 5-fluorosalicylic acid: description of a new polymorph

2018 ◽  
Vol 74 (1) ◽  
pp. 1-6
Author(s):  
Martin Lutz ◽  
Jara F. Vliem ◽  
Hendrik P. Rodenburg
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Monoclinic Crystal System ◽  
Asymmetric Unit ◽  
Group Setting ◽  
Unit Cell Parameters ◽  
Monoclinic Crystal ◽  
Acta Cryst ◽  
Cell Parameters ◽  
Crystal System

The crystal structure of 5-fluorosalicylic acid is known from the literature [Choudhury & Guru Row (2004). Acta Cryst. E60, o1595–o1597] as crystallizing in the monoclinic crystal system with space-group setting P21/n and with one molecule in the asymmetric unit (polymorph I). We describe here a new polymorph which is again monoclinic but with different unit-cell parameters (polymorph II). Polymorph II has two molecules in the asymmetric unit. Its structure was modelled as a twin, with a pseudo-orthorhombic C-centred twin cell.

Darstellung und Charakterisierung der Carbosilazane Bis[tris(methylamino)silyl]methan und Bis[tris(phenylamino)silyl]methan/Preparation and Characterization of the Carbosilazanes Bis[tris(methylamino)silyl]methane and B is[tris(phenylamino)silyl]m ethane

1997 ◽  
Vol 52 (6) ◽  
pp. 707-710
Author(s):  
M. Jansen ◽  
S. Bzik
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters

Bis[tris(methylamino)silyl]methane (1) and bis[tris(phenylamino)silyl]methane (2) have been synthesized as potential precursors of porous oxygen-free solids by the reaction of bis(trichlorsilyl)methane with methylamine and with lithiated aniline, respectively. Compound 2 was characterized by a crystal structure analysis. It crystallizes in the monoclinic space group P 21 ,/c with the unit cell parameters a= 10.963(2),b= 17.801(2), c = 17.557(2) Å, β = 97.96(2)° and Z = 4 (R1, = 4,4 %, wR2 = 9,8 %, 5950 independent reflections).

scholarly journals Crystal structure and characterization of magnesium carbonate chloride heptahydrate

2020 ◽  
Vol 76 (8) ◽  
pp. 741-745
Author(s):  
Christine Rincke ◽  
Horst Schmidt ◽  
Gernot Buth ◽  
Wolfgang Voigt
Keyword(s):  
Crystal Structure ◽  
Magnesium Carbonate ◽  
Chloride Ions ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure ◽  
Structure Solution ◽  
Concentrated Solution

MgCO3·MgCl2·7H2O is the only known neutral magnesium carbonate containing chloride ions at ambient conditions. According to the literature, only small and twinned crystals of this double salt could be synthesised in a concentrated solution of MgCl2. For the crystal structure solution, single-crystal diffraction was carried out at a synchrotron radiation source. The monoclinic crystal structure (space group Cc) exhibits double chains of MgO octahedra linked by corners, connected by carbonate units and water molecules. The chloride ions are positioned between these double chains parallel to the (100) plane. Dry MgCO3·MgCl2·7H2O decomposes in the air to chlorartinite, Mg2(OH)Cl(CO3)·nH2O (n = 2 or 3). This work includes an extensive characterization of the title compound by powder X-ray diffraction, thermal analysis, SEM and vibrational spectroscopy.

A Crystallographic Study of Bis[S-benzyl-5-bromo-2-oxoindolin-3-ylidenemethanehydrazonthioate] Disulfide Solvated with Dimethylsulfoxide

2012 ◽  
Vol 9 (2) ◽  
pp. 87
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
M. Ibrahim M. Tahir ◽  
Karen A. Crouse ◽  
Fiona N.-F. How ◽  
David J. Watkin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Solvent Molecule ◽  
Site Occupancy ◽  
Unit Cell Parameters ◽  
Intermolecular Hydrogen Bonds ◽  
Triclinic Space Group ◽  
Cell Parameters ◽  
Crystallographic Study ◽  
Thiol Form

The crystal structure of the title compound has been determined. The compound crystallized in the triclinic space group P -1, Z = 2, V = 1839 .42( 18) A3 and unit cell parameters a= 11. 0460( 6) A, b = 13 .3180(7) A, c=13. 7321 (8) A, a = 80.659(3 )0, b = 69 .800(3 )0 and g = 77 .007 (2)0 with one disordered dimethylsulfoxide solvent molecule with the sulfur and oxygen atoms are distributed over two sites; S101/S102 [site occupancy factors: 0.6035/0.3965] and 0130/0131 [site occupancy factor 0.3965/0.6035]. The C22-S2 l and C 19-S20 bond distances of 1. 779(7) A and 1. 788(8) A indicate that both of the molecules are connected by the disulfide bond [S20-S21 2.055(2) A] in its thiol form. The crystal structure reveals that both of the 5-bromoisatin moieties are trans with respect to the [S21-S20 and CI 9-Nl 8] and [S20-S21 and C22-N23] bonds whereas the benzyl group from the dithiocarbazate are in the cis configuration with respect to [S21-S20 and C19-S44] and [S20-S21 and C22-S36] bonds. The crystal structure is further stabilized by intermolecular hydrogen bonds of N9-H35···O16 formed between the two molecules and N28-H281 ···O130, N28-H281 ···O131 and C4 l-H4 l l ···O 131 with the solvent molecule.

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

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