Embreyite: structure determination, chemical formula and comparative crystal chemistry

2018 ◽  
Vol 82 (2) ◽  
pp. 275-290 ◽  
Author(s):  
Vadim M. Kovrugin ◽  
Oleg I. Siidra ◽  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Dmitry A. Khanin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Microprobe Analysis ◽  
Direct Methods ◽  
Structural Similarity ◽  
Structural Type ◽  
Unit Cell ◽  
Single Crystal Xrd ◽  
Cell Parameters ◽  
Distorted Octahedra

ABSTRACTEmbreyite from the Berezovskoe, Urals, Russia, was studied by the means of powder X-ray diffraction (XRD), single-crystal XRD, infrared spectroscopy and microprobe analysis. The empirical formula of embreyite obtained on the basis of microprobe analysis is Pb1.29Cu0.07Cr0.52P0.43O4(without taking into account the presence of H2O). An examination of single-crystal XRD frames of the tested crystals cut from embreyite intergrowths revealed split reflection spots of weak intensities, even after a long exposure time. The crystal structure of embreyite (monoclinic,C2/m,a= 9.802(16),b= 5.603(9),c= 7.649(12) Å, β = 114.85(3)oandV= 381.2(11) Å3) has been solved by direct methods and refined toR1= 0.050 for 318 unique observed reflections. The powder XRD patterns of the holotype embreyite and the fresh material studied are close in bothdvalues and the intensities match the pattern calculated from the structural single-crystal XRD data. The unit-cell parameters were re-calculated for the holotype sample using a new cell setting and correspondinghklindices. The crystal structure of embreyite is based on layers formed by corner-sharing mixed chromate-phosphate tetrahedra and PbO6distorted octahedra. The interlayer space is filled by disordered Pb2+and Cu2+cations. Generally, the crystal structure of embreyite can be referred to the structural type of palmierite. {Pb[(Cr,P)O4]2]} layers in embreyite are similar in topology to those in yavapaiite-type compounds. The general formula of embreyite can be represented as (Pbx$M_y^{2 +} $□1–x–y)2{Pb[(Cr,P)O4]2}(H2O)n, whereM2+= Cu and Zn and 0.5 ≤x+y≤ 1, or, in the simplified form: (Pb,Cu,□)2{Pb[(Cr,P)O4]2}(H2O)n. The simplified formula of embreyite is similar in stoichiometry to vauquelinite and may explain the existence of the solid-solution series. The determination of the crystal structure of embreyite may also help to resolve the crystal chemical nature of cassedanneite. The XRD pattern of cassedanneite contains a distinct reflection withd= 13.9 Å, forbidden for the embreyite unit cell. This feature may indicate the doubling of thecunit-cell parameter of cassedanneite in comparison with embreyite. We assume that cassedanneite has structural similarity to embreyite with, presumably, a disordered distribution of Cr and V.

Redefinition of satimolite

2018 ◽  
Vol 82 (5) ◽  
pp. 1033-1047 ◽  
Author(s):  
Igor V. Pekov ◽  
Natalia V. Zubkova ◽  
Dmitry A. Ksenofontov ◽  
Nikita V. Chukanov ◽  
Vasiliy O. Yapaskurt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Direct Methods ◽  
Salt Dome ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Octahedral Clusters

ABSTRACTThe borate mineral satimolite, which was first described in 1969 and remained poorly-studied until now, has been re-investigated (electron microprobe analysis, single-crystal and powder X-ray diffraction studies, crystal-structure determination, infrared spectroscopy) and redefined based on the novel data obtained for the holotype material from the Satimola salt dome and a recently found sample from the Chelkar salt dome, both in North Caspian Region, Western Kazakhstan. The revised idealized formula of satimolite is KNa2(Al5Mg2)[B12O18(OH)12](OH)6Cl4·4H2O (Z = 3). The mineral is trigonal, space group R$\bar{3}$m, unit-cell parameters are: a = 15.1431(8), c = 14.4558(14) Å and V = 2870.8(4) Å3 (Satimola) and a = 15.1406(4), c = 14.3794(9) Å and V = 2854.7(2) Å3 (Chelkar). The crystal system and unit-cell parameters are quite different from those reported previously. The crystal structure of the sample from Chelkar was solved based on single-crystal data (direct methods, R = 0.0814) and the structure of the holotype from Satimola was refined on a powder sample by the Rietveld method (Rp = 0.0563, Rwp = 0.0761 and Rall = 0.0667). The structure of satimolite is unique for minerals. It contains 12-membered borate rings [B12O18(OH)12] in which BO3 triangles alternate with BO2(OH)2 tetrahedra sharing common vertices, and octahedral clusters [M7O6(OH)18] with M = Al5Mg2 in the ideal case, with sharing of corners between rings and clusters to form a three-dimensional heteropolyhedral framework. Each borate ring is connected with six octahedral clusters: three under the ring and three over the ring. Large ellipsoidal cages in the framework host Na and K cations, Cl anions and H2O molecules.

Waimirite-(Y), orthorhombic YF3, a new mineral from the Pitinga mine, Presidente Figueiredo, Amazonas, Brazil and from Jabal Tawlah, Saudi Arabia: description and crystal structure

2015 ◽  
Vol 79 (3) ◽  
pp. 767-780 ◽  
Author(s):  
Daniel Atencio ◽  
Artur C. Bastos Neto ◽  
Vitor P. Pereira ◽  
José T. M. M. Ferron ◽  
M. Hoshino ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Saudi Arabia ◽  
Single Crystal ◽  
Electron Microprobe ◽  
Empirical Formula ◽  
Unit Cell ◽  
New Mineral ◽  
Charge Balance ◽  
Unit Cell Parameters ◽  
Cell Parameters

AbstractWaimirite-(Y) (IMA 2013-108), orthorhombic YF3, occurs associated with halloysite, in hydrothermal veins (up to 30 mm thick) cross-cutting the albite-enriched facies of the A-type Madeira granite (∼1820 Ma), at the Pitinga mine, Presidente Figueiredo Co., Amazonas State, Brazil. Minerals in the granite are 'K-feldspar', albite, quartz, riebeckite, 'biotite', muscovite, cryolite, zircon, polylithionite, cassiterite, pyrochlore-group minerals, 'columbite', thorite, native lead, hematite, galena, fluorite, xenotime-(Y), gagarinite-(Y), fluocerite-(Ce), genthelvite–helvite, topaz, 'illite', kaolinite and 'chlorite'. The mineral occurs as massive aggregates of platy crystals up to ∼1 μm in size. Forms are not determined, but synthetic YF3 displays pinacoids, prisms and bipyramids. Colour: pale pink. Streak: white. Lustre: non-metallic. Transparent to translucent. Density (calc.) = 5.586 g/cm3 using the empirical formula. Waimirite-(Y) is biaxial, mean n = 1.54–1.56. The chemical composition is (average of 24 wavelength dispersive spectroscopy mode electron microprobe analyses, O calculated for charge balance): F 29.27, Ca 0.83, Y 37.25, La 0.19, Ce 0.30, Pr 0.15, Nd 0.65, Sm 0.74, Gd 1.86, Tb 0.78, Dy 8.06, Ho 1.85, Er 6.38, Tm 1.00, Yb 5.52, Lu 0.65, O (2.05), total (97.53) wt.%. The empirical formula (based on 1 cation) is (Y0.69Dy0.08Er0.06Yb0.05Ca0.03Gd0.02Ho0.02Nd0.01Sm0.01Tb0.01Tm0.01Lu0.01)Σ1.00[F2.54〈0.25O0.21]Σ3.00. Orthorhombic, Pnma, a = 6.386(1), b = 6.877(1), c = 4.401(1) Å, V = 193.28(7) Å3, Z = 4 (powder data). Powder X-ray diffraction (XRD) data [d in Å (I) (hkl)]: 3.707 (26) (011), 3.623 (78) (101), 3.438 (99) (020), 3.205 (100) (111), 2.894 (59) (210), 1.937 (33) (131), 1.916 (24) (301), 1.862 (27) (230). The name is for the Waimiri-Atroari Indian people of Roraima and Amazonas. A second occurrence of waimirite-(Y) is described from the hydrothermally altered quartz-rich microgranite at Jabal Tawlah, Saudi Arabia. Electron microprobe analyses gave the empirical formula (Y0.79Dy0.08Er0.05Gd0.03Ho0.02Tb0.01Tm0.01Yb0.01)Σ1.00[F2.85O0.08〈0.07]Σ3.00. The crystal structure was determined with a single crystal from Saudi Arabia. Unit-cell parameters refined from single-crystal XRD data are a = 6.38270(12), b = 6.86727(12), c = 4.39168(8) Å, V = 192.495(6) Å3, Z = 4. The refinement converged to R1 = 0.0173 and wR2 = 0.0388 for 193 independent reflections. Waimirite-(Y) is isomorphous with synthetic SmF3, HoF3 and YbF3. The Y atom forms a 9-coordinated YF9 tricapped trigonal prism in the crystal structure. The substitution of Y for Dy, as well as for other lanthanoids, causes no notable deviations in the crystallographic values, such as unit-cell parameters and interatomic distances, from those of pure YF3.

X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

1998 ◽  
Vol 54 (4) ◽  
pp. 358-364 ◽  
Author(s):  
K. G. Hatzisymeon ◽  
S. C. Kokkou ◽  
A. N. Anagnostopoulos ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

Synthese und Kristallstruktur von Triphenyltelluroniumsulfid / Synthesis and Crystal Structure of Triphenyltelluroniumsulfide

1994 ◽  
Vol 49 (12) ◽  
pp. 1654-1658 ◽  
Author(s):  
Markus Wieber ◽  
Stefan Lang ◽  
Stefan Rohse ◽  
Ralph Habersack ◽  
Christian Burschka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Title Compound ◽  
Spectroscopic Characterization ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Cell Parameters

The synthesis of triphenyltelluroniumsulfide (Ph3TeS)4 is described together with a NMR-spectroscopic characterization. The structure of the title compound was determined by single crystal X-ray diffraction. Crystals of triphenyltelluroniumsulfide are triclinic (space group P1) with the cell parameters a = 1178.0(3) pm. b = 1295.8(6) pm. c = 1298.7(4) pm, α = 77.67(3)°, β = 82.18(2)°, γ = 66.00(2)° (V = 1766(1) × 106 pm3) and Z = 2. The compound appears to form a step-like structure of two [Ph3TeS]2 units and crystallizes with two molecules of CH2Cl2 per unit cell.

scholarly journals New data on gersdorffite and associated minerals from the Peloritani Mountains (Sicily, Italy)

2021 ◽  
Vol 33 (6) ◽  
pp. 717-726
Author(s):  
Daniela Mauro ◽  
Cristian Biagioni ◽  
Federica Zaccarini
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Quartz Veins ◽  
Group I

Abstract. Gersdorffite, ideally NiAsS, and associated minerals from Contrada Zillì (Peloritani Mountains, Sicily, Italy) have been characterized through electron microprobe analysis and X-ray diffraction. Primary minerals, hosted in quartz veins, are represented by gersdorffite, tetrahedrite-(Fe), and chalcopyrite with minor pyrite and galena. Rare aikinite inclusions were observed in tetrahedrite-(Fe) and chalcopyrite. Gersdorffite occurs as euhedral to subhedral crystals, up to 1 mm in size, with (Sb,Bi)-enriched cores and (Fe,As)-enriched rims. Its chemical composition is (Ni0.79−0.95Fe0.18−0.04Co0.04−0.01)(As0.90−1.03Sb0.10−0.00Bi0.02−0.00)S0.98−0.92. It crystallizes in the space group P213, with unit-cell parameters a=5.6968(7) Å, V=184.88(7) Å3, and Z=4, and its crystal structure was refined down to R1= 0.035. Associated tetrahedrite-(Fe) has chemical formula (Cu5.79Ag0.07)Σ5.86(Cu3.96Fe1.59Zn0.45)Σ6.00(Sb3.95As0.17Bi0.03)Σ4.15S13.06, with unit-cell parameters a= 10.3815(10) Å, V=1118.9(3) Å3, and space group I-43m. Its crystal structure was refined to R1=0.027. Textural and crystallographic data suggest a polyphasic crystallization of gersdorffite under low-temperature conditions.

scholarly journals Crystal structure of gluconate 5-dehydrogenase from Lentibacter algarum

2020 ◽  
Vol 76 (5) ◽  
pp. 228-234
Author(s):  
Dengke Tian ◽  
Xueqi Fu ◽  
Wenqiang Cao ◽  
Hong Yuan
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Structural Similarity ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
Cell Parameters ◽  
High Structural Similarity

Gluconate 5-dehydrogenase (Ga5DH; EC 1.1.1.69) from Lentibacter algarum (LaGa5DH) was recombinantly expressed in Escherichia coli and purified to homogeneity. The protein was crystallized and the crystal structure was solved at 2.1 Å resolution. The crystal belonged to the monoclinic system, with space group P1 and unit-cell parameters a = 55.42, b = 55.48, c = 79.16 Å, α = 100.51, β = 105.66, γ = 97.99°. The structure revealed LaGaDH to be a tetramer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. LaGa5DH has high structural similarity to other Ga5DH proteins, demonstrating that this enzyme is highly conserved.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

Structure of Pb-rich chabournéite from Jas Roux, France

2015 ◽  
Vol 71 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Cristian Biagioni ◽  
Yves Moëlo ◽  
Georges Favreau ◽  
Vincent Bourgoin ◽  
Jean-Claude Boulliard
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Structural Formula ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Cation Sites ◽  
Pyramidal Groups

The crystal structure of a specimen of `Pb-rich' chabournéite from Jas Roux, Hautes-Alpes, France, with the chemical formula obtained by electron microprobe analysis of Ag0.04 (1)Tl2.15 (2)Pb0.64 (1)Sb5.12 (1)As5.05 (1)S17.32 (5), has been solved by X-ray single-crystal diffraction on the basis of 36 550 observed reflections (withFo> 4σFo) with a finalR1= 0.074. Pb-rich chabournéite is triclinicP1, with unit-cell parametersa= 8.5197 (4),b= 42.461 (2),c= 16.293 (8) Å, α = 83.351 (2), β = 90.958 (2), γ = 84.275 (2)°,V= 5823 (3) Å3. Its structural formula is close to [Tl2(Pb0.8Tl0.1Sb1.1)](Sb4.1As4.9)S17, withZ= 8. Its crystal structure is formed by the alternation of two pairs of slabs along thebaxis, deriving from the SnS and PbS archetypes, respectively. 104 independent cation sites and 136 S sites occur in the unit cell. Slab interfaces show the alternation, alongc, of Tl sites, ninefold coordinated, with Pb, Sb or mixed/split (Pb,Sb) and (Pb,Tl) sites. Within the slabs, 72 independentM3+sites (M3+= As, Sb) occur. ConsideringM3+—S bond distances shorter than 2.70 Å,MS3triangular pyramidal groups are condensed according to variousMmSnchain fragments (`polymers'). The solution of the crystal structure of chabournéite allows its comparison with the closely related homeotypes protochabournéite and dalnegroite.

Reactions between Co(II), 1,2-bis(diphenylphosphino)ethane, and NaBH3CN in the presence and absence of CO. The crystal structure of bis(cyanotrihydroborato)tetrakis(N,N-dimethylformamide)cobalt(II)

1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
R Factor

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.

Crystallographic studies of cobalt arsenates. IV. Crystal parameters of cobalt diarsenate

1970 ◽  
Vol 48 (2) ◽  
pp. 388-389 ◽  
Author(s):  
J. Ozog ◽  
N. Krishnamachari ◽  
C. Calvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Triclinic Unit Cell ◽  
Measured Density

The crystal structure of cobalt diarsenate has been shown to be a new member of a series of structures closely related to that of the mineral thortveitite. The triclinic unit cell parameters are: a = 6.55 Å, b = 8.52 Å, c = 4.76 Å, α = 91.0°, β = 104.0°, γ = 91.3°. There are 2 molecules per unit cell with a symmetry Cl or [Formula: see text] and a measured density 5.01 g/cm3. The single crystal patterns show nearly the C2/m symmetry characteristic of the mineral thortveitite and its analogues.

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