Crystal structure and crystal chemistry of biehlite, Sb1.79As0.21MoO6

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
G. Adiwidjaja ◽  
Karen Friese ◽  
K.-H. Klaska ◽  
J. Schlüter ◽  
M. Czank
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry ◽  
Lone Pair ◽  
New Mineral ◽  
Calculated Distance ◽  
Oxygen Atoms

The new mineral biehlite was found in the Tsumeb mine, Namibia and has the composition Sb[MoOThe [MoOThe Sb-cation forms three short bonds with oxygen at distances slightly smaller than 2Å. Six further oxygen atoms are located at distances ranging from 2.910(6) to 3.470(6)Å. Calculated distance for the lone-pair is 1.18 Å. Part of the Sb

The crystal structure of kamchatkite, a new naturally occurring oxychloride sulphate of potassium and copper

1990 ◽  
Vol 54 (377) ◽  
pp. 613-616 ◽  
Author(s):  
T. V. Varaksina ◽  
V. S. Fundamensky ◽  
S.K. Filatov ◽  
L. P. Vergasova
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Direct Methods ◽  
New Mineral ◽  
Space Group ◽  
Naturally Occurring ◽  
Discrepancy Index ◽  
Oxygen Atoms

AbstractThe crystal structure of the new mineral kamchatkite, a= 9.741(5), b= 12.858(6), c=7.001(3)Å, space group Pna21, Z = 4, has been determined through direct methods using 1430 intensities and refined to a final discrepancy index R = 0.055. It contains (SO4) tetrahedra and Cu octahedra interconnected by oxygen atoms to form an electrostatically neutral three-dimensional arrangement of formula Cu3O[SO4]2 which contains channels parallel to [001]. The channels are not empty but house KCl molecules.

Crystal chemistry of inorganic compounds based on chains of oxocentered tetrahedra III. Crystal structure of georgbokiite, Cu5O2(SeO3)2Cl21

1999 ◽  
Vol 214 (3) ◽  
Author(s):  
S. V. Krivovichev ◽  
R. R. Shuvalov ◽  
T. F. Semenova ◽  
S. K. Filatov
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Crystal Chemistry ◽  
Inorganic Compounds ◽  
New Mineral ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure

AbstractThe monoclinic crystal structure of georgbokiite, a new mineral with the chemical composition Cu

The crystal structure of balićžunićite, Bi2O(SO4)2, a new natural bismuth oxide sulfate

2015 ◽  
Vol 79 (3) ◽  
pp. 597-611 ◽  
Author(s):  
Daniela Pinto ◽  
Anna Garavelli ◽  
Tonci Balić-Žunić
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Building Blocks ◽  
New Mineral ◽  
X Ray Diffraction ◽  
New Mineral Species ◽  
Coordination Spheres ◽  
High Temperature Polymorph ◽  
Fossa Crater ◽  
Oxygen Atoms

AbstractThe crystal structure of balićžunićite, Bi2O(SO4)2, a new mineral species from the La Fossa crater of Vulcano (Aeolian Islands, Italy), was solved from single-crystal X-ray diffraction data and refined to R = 0.0507. The structure is triclinic, space group P1, with a = 6.7386(3), b = 11.1844(5), c = 14.1754(7) Å, α = 80.082(2), β = 88.462(2)°, γ = 89.517(2)°, V = 1052.01(8) Å3 and Z = 6. The crystal structure consists of six independent Bi sites, six S sites and 27 O sites of which three are oxo oxygen atoms not bonded to sulfur. Bismuth and S atoms are arranged close to a eutectic pattern parallel to the (100) plane. The planes are stacked atom on atom such that Bi always overlays S and vice versa. This structural feature is shared with the known structure of the high-temperature polymorph of the same compound, stable at T >535°C. However, the sequences of Bi and S atoms in the two structures are different and so are the arrangements of oxygen atoms. Characteristic building blocks in the structure of balićžunićite are clusters of five Bi atoms which form nearly planar trapezoidal Bi5 groups with oxo oxygens located in the centres of the three Bi3 triangles, which form the trapezoids. The trapezoidal Bi5O39+ ions are joined along [100] with SO42– groups by means of strong bismuth-sulfate oxygen bonds, forming infinite [100] rods with composition Bi5O3(SO4)5–. One sixth of the Bi atoms do not participate in trapezoids, but form, with additional SO42– groups, rows of composition BiSO4+, also parallel to [100]. [Bi5O3(SO4)5–] rods form infinite layers parallel to (010) with [BiSO4+] rows located on the irregular surface of contact between adjacent layers. Bi atoms occur in four different coordination types, all showing the stereochemical influence of the Bi3+ lone electron pair. In this respect the crystal structure of balićžunićite shows greater variability than its high-temperature polymorph which has only two types of the Bi coordination spheres present in balićžunićite.

scholarly journals Zoisite-(Pb), a New Orthorhombic Epidote-Related Mineral from the Jakobsberg Mine, Värmland, Sweden, and Its Relationships with Hancockite

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Natale Perchiazzi ◽  
Daniela Mauro ◽  
Pietro Vignola ◽  
Federica Zaccarini ◽  
Knut Eldjarn
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Structural Model ◽  
Electron Microprobe Analysis ◽  
Lone Pair ◽  
New Mineral ◽  
Oxide Deposit ◽  
Crystal Structural ◽  
Raman Characterization

The new mineral zoisite-(Pb), ideally CaPbAl3(SiO4)(Si2O7)O(OH), was discovered in a sample from the Jakobsberg manganese-iron oxide deposit, Värmland, Sweden. Zoisite-(Pb) is found as pale pink subhedral prisms elongated on [010], up to 0.3 mm in size, associated with calcite, celsian, diopside, grossular, hancockite, hyalophane, native lead, phlogopite, and vesuvianite. Associated feldspars show one of the highest PbO contents (~7–8 wt%) found in nature. Electron-microprobe analysis of zoisite-(Pb) point to the empirical formula (Ca1.09Pb0.86Mn2+0.01Na0.01)∑1.97(Al2.88Fe3+0.10Mn3+0.04)∑3.02Si3.00O12(OH)1.00. The eight strongest diffraction lines [dobs, Iobs, (hkl)] are 8.63 s (101), 8.11 mw (200), 4.895 m (011), 4.210 m (211), 3.660 s (112, 311), 3.097 mw (312), 2.900 s (013), and 2.725 m (511). Zoisite-(Pb) is isostructural with zoisite and its crystal structure was refined up to R1 = 0.0213 for 2013 reflections with Fo > 4σ(Fo). Pb shows a stereochemically active lone pair leading to a lopsided distribution of its coordinating oxygens. A full chemical and Raman characterization of zoisite-(Pb) and of the Pb-bearing epidote hancockite is reported, together with an improved crystal structural model of hancockite, refined up to R1 = 0.0254 for 2041 reflections with Fo > 4σ(Fo). The effects of the incorporation of Pb in the crystal structure of zoisite-(Pb), hancockite, and related synthetic and natural phases are described and discussed.

scholarly journals The crystal structure of a new CdTe2O5 polymorph, isotypic with ∊-CaTe2O5

2020 ◽  
Vol 76 (6) ◽  
pp. 831-834
Author(s):  
Felix Eder ◽  
Matthias Weil
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Reaction ◽  
Lone Pair ◽  
Quantitative Comparison ◽  
The Other ◽  
Asymmetric Unit ◽  
Molar Ratios ◽  
Wyckoff Position ◽  
By Products ◽  
Oxygen Atoms

Single crystals of cadmium pentaoxidoditellurate(IV), CdTe2O5, were obtained as by-products in a hydrothermal reaction of Cd(NO3)2·4H2O, TeO2, H6TeO6 and NH3 (molar ratios 2:1:1:6) at 483 K for seven days. The crystals represent a different polymorph (henceforth referred to as the β-form) than the α-CdTe2O5 crystals grown from the melt, and are isotypic with hydrothermally grown ∊-CaTe2O5. The asymmetric unit of β-CdTe2O5 comprises one Cd, two Te and five O sites, all of which are located in general positions (Wyckoff position 4 e). The cadmium(II) atom is coordinated by seven oxygen atoms, forming 2 ∞[CdO6/2O1/1] (100) layers. Both tellurium sites are surrounded by four oxygen atoms with one of them being at a significantly longer distance than the other three. The resulting bisphenoidal [TeO4] units also form layers propagating parallel to (100) by sharing edges with each other. The stereochemically active 5s 2 lone pair of the TeIV atoms leads to the formation of large channels extending along [011] and smaller ones along [010]. A quantitative comparison between the crystal structures of β-CdTe2O5 and ∊-CaTe2O5 is made.

Oxotellurate(IV) der Lanthanide: I. Die isotype Reihe M2Te4O11 (M = La – Nd, Sm – Yb)

2004 ◽  
Vol 59 (8) ◽  
pp. 881-888 ◽  
Author(s):  
Steffen F. Meier ◽  
Thomas Schleid
Keyword(s):  
Crystal Structure ◽  
Coordination Sphere ◽  
Lone Pair ◽  
Double Layers ◽  
Experimental Investigations ◽  
Partial Structure ◽  
Secondary Coordination Sphere ◽  
Active Electron ◽  
The Stability ◽  
Oxygen Atoms

AbstractThe present work is the first comprehensive account of the knowledge acquired from single crystals of the isotopic series M2Te4O11 (M = La - Nd, Sm - Yb). In the crystal structure, the M3+ cation is coordinated by eight oxygen atoms in the shape of a distorted square antiprism. Out of these polyhedra a mesh-like [M2O16]14− layer parallel to the (001) plane is built via three common edges. The [Te4O11]6− double layers in turn build two tellurium-oxygen chains crosswise to each other. The construction of the tellurium-oxygen partial structure is, however, only possible taking the secondary Te-O contacts into consideration. In most oxotellurates(IV), three oxygen atoms are covalently bound to the Te atoms (d(Te-O) ≈ 180−200 pm; ψ1 tetrahedron). Another oxygen atom is found in the near vicinity at a distance of 230 to 280 pm. The significance of such secondary interactions for the stability of the crystal structures was recognized recently in theoretical as well as experimental investigations. All oxygen atoms with distances smaller than 280 pm are counted to the secondary coordination sphere. This limit may seem somewhat arbitrary but it accounts very well for the Te-O partial structure. The coordination sphere for the tellurium center is a ψ1 trigonal bipyramid including the stereochemically active electron pair (“lone pair”). A description of the crystal structure is also possible without this partial structure, however in the [TeO3+1]4− polyhedra above and below the meshes of [M2O10]14− layers are linked via Te2-O6-Te2 contacts only.

Štěpite, U(AsO3OH)2·4H2O, from Jáchymov, Czech Republic: the first natural arsenate of tetravalent uranium

2013 ◽  
Vol 77 (1) ◽  
pp. 137-152 ◽  
Author(s):  
J. Plášil ◽  
K. Fejfarová ◽  
J. Hloušek ◽  
R. Škoda ◽  
M. Novák ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Czech Republic ◽  
Uranium Atom ◽  
Short Wave ◽  
New Mineral ◽  
Oh Groups ◽  
X Ray ◽  
Tetravalent Uranium ◽  
Mohs Hardness ◽  
Oxygen Atoms

AbstractŠtěpite, tetragonal U(AsO3 OH)2(H2O)4 (IMA 2012-006), is the first natural arsenate of tetravalent uranium. It occurs in the Geschieber vein, Jáchymov ore district, Western Bohemia, Czech Republic, as emerald-green crystalline crusts on altered arsenic. Associated minerals include arsenolite, běhounekite, claudetite, gypsum, kaatialaite, the new mineral vysokýite (IMA 2012-067) and a partially characterized phase with the formula (H3O)+2(UO2)2(AsO4)2˙6H2O. Štěpite typically forms tabular crystals with prominent {001} and {010} faces, up to 0.6 mm in size. The crystals have a vitreous lustre and a grey to greenish grey streak. They are brittle with an uneven fracture and a very good cleavage on (001). Their Mohs hardness is about 2. Štěpite is not fluorescent in either short-wave or long-wave ultraviolet light. It is biaxial (–) with refractive indices (at 590 nm) of α = 1.636(2), β = 1.667(3), γ = 1.672(2) and 2Vobs < ~5°, anomalous greyish to pale yellow interference colours, and no pleochroism. The composition is as follows: 0.12Na2O, 50.19 UO2, 0.04SiO4, 0.09 P2O5, 0.93 As2O5, 1.95 SO3, 16.41 H2O; total 107.90 wt.%, yielding an empirical formula (based on 12 O a. p. f. u.) of (U1.01Na0.02)Σ1.03[(AsO3OH)1.82 (PO3OH)0.04(SO4)0.13(SiO4)0.01]Σ 2.00˙4H2O. Štěpite is tetragonal, crystallizing in space group I41/acd, with a = 10.9894(1), c = 32.9109(6) Å, V = 3974.5(1) Å3, Z = 16 and Dcalc = 3.90 g cm-3. The six strongest peaks in the X-ray powder-diffraction pattern [dobs in Å (I) (hkl)] are as follows: 8.190(100)(004), 7.008(43)(112), 5.475(18)(200), 4.111(16)(008), 3.395(20)(312,217), 2.1543(25)(419). The crystal structure of šteěpite has been solved from singlecrystal X-ray diffraction data by the charge-flipping method and refined to R1 = 0.0353 based on 1434 unique observed reflections, and to wR2 = 0.1488 for all 1523 unique reflections. The crystal structure of štšpite consists of sheets perpendicular to [001], made up of eight-coordinate uranium atoms and hydroxyarsenate 'tetrahedra'. The ligands surrounding the uranium atom consist of six oxygen atoms which belong to the hydroxyarsenate groups and two oxygen atoms which belong to interlayer H2 O molecules. Each UO8 polyhedron is connected to five other U polyhedra via six AsO3OH groups. Adjacent electroneutral sheets, of composition [U4+(AsO3OH)22-]0, are linked by hydrogen bonds involving H2 O molecules in the interlayers and OH groups in the sheets. The new mineral is named in honour of Josef Štěp (1863–1926), a Czech mining engineer and 'father' of the world's first radioactive spa at Jáchymov.

Mercury-arsenic sulfosalts from the Apuan Alps (Tuscany, Italy). II. Arsiccioite, AgHg2TlAs2S6, a new mineral from the Monte Arsiccio mine: occurrence, crystal structure and crystal chemistry of the routhierite isotypic series

2014 ◽  
Vol 78 (1) ◽  
pp. 101-117 ◽  
Author(s):  
C. Biagioni ◽  
E. Bonaccorsi ◽  
Y. Moëlo ◽  
P. Orlandi ◽  
L. Bindi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry ◽  
Three Dimensional ◽  
New Mineral ◽  
Chemical Formula ◽  
New Mineral Species ◽  
Ore Minerals ◽  
Reflectance Data ◽  
Apuan Alps ◽  
The Ideal

AbstractThe new mineral species arsiccioite, AgHg2TlAs2S6, was discovered in the baryte-pyrite-iron oxide ore deposit exploited at the Monte Arsiccio mine, near Sant’Anna di Stazzema (Apuan Alps, Tuscany, Italy). It occurs as anhedral grains scattered in microcrystalline baryte, associated with cinnabar, laffittite, protochabournéite, pyrite, realgar, Hg-bearing sphalerite and stibnite. Arsiccioite is red, with a metallic to sub-metallic lustre. Minimum and maximum reflectance data for COM wavelengths in air are [λ (nm):R(%)]: 471.1: 29.0/29.4; 548.3: 27.6/28.3; 586.6: 26.1/26.5; 652.3: 24.2/24.6. Electron microprobe analyses give (wt.%): Cu 0.78(6), Ag 8.68(21), Zn 0.47(27), Fe 0.04(1), Hg 35.36(87), Cd 0.20(5), Tl 18.79(33), As 10.77(19), Sb 4.75(10), S 18.08(21), Se 0.07(5), total 97.99(44). On the basis of ΣMe= 6 a.p.f.u., the chemical formula is Ag0.87(2)Cu0.13(1)Zn0.08(4)Fe0.01(1)Hg1.91(5)Cd0.02(1)Tl1.00(2)(As1.56(2)Sb0.42(1))S1.98S6.12(6)Se0.01(1). Arsiccioite is tetragonal,I2m, witha10.1386(6),c11.3441(5) Å,V1166.1(2) Å3,Z= 4. The main diffraction lines of the powder diagram are [d(in Å), visually estimated intensity,hkl]: 4.195, m, 211; 3.542, m, 103; 3.025, vs, 222; 2.636, m, 114; 2.518, s, 400 and 303. The crystal structure of arsiccioite has been refined by single-crystal X-ray data to a finalR1= 0.030, on the basis of 893 observed reflections. It shows a three dimensional framework of (Hg,Ag)- centred tetrahedra (1M1 + 2M2), with channels parallel to [001] hosting TlS6and (As,Sb)S3 disymmetric polyhedra. Arsiccioite is derived from its isotype routhieriteM1CuM2Hg2TlAs2S6through the double heterovalent substitutionM1Cu++M2Hg2+→M1Hg2++M2Ag+. This substitution obeys a steric constraint, with Ag+, the largest cation relative to Hg2+and Cu+, entering the largestM2 site. The ideal crystal chemical formula of arsiccioite isM1HgM2(Hg0.5Ag0.5)2TlAs2S6. The crystal chemistry of the routhierite isotypic series is discussed. Finally, the distribution of Hg ore minerals in the Apuan Alps is reviewed.

Syntheses and Characterization of Two New Lead(II) Acetate Complexes, Pb(L)(CH3COO)2, L = 2,2':6',2''-Terpyridine (tpy) and 2,4,6-Tris(2-pyridyl)- 1,3,5-Triazine (trz), Crystal Structure of Pb(tpy)(CH3COO)2

2004 ◽  
Vol 59 (9) ◽  
pp. 1039-1044 ◽  
Author(s):  
Ali Morsali
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Lone Pair ◽  
Aromatic Rings ◽  
X Ray ◽  
Π Stacking ◽  
Coordinate Geometry ◽  
Oxygen Atoms

Lead(II) complexes with 2,2':6',2''-terpyridine (tpy) and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (trz) ligands, [Pb(tpy)(CH3COO)2] and [Pb(trz)(CH3COO)2], have been synthesized and characterized by IR, CHN elemental analysis and 207Pb NMR. The structure of Pb(tpy)(CH3COO)2 was confirmed by single crystal X-ray data. The complex is monomeric and the Pb atom has an unsymmetrical seven-coordinate geometry, being coordinated by three nitrogen atoms of the 2,2’:6’,2”-terpyridine ligand and four oxygen atoms of the CH3COO− ligands. The arrangement of the ligands in the two complexes exhibits a coordination gap around the Pb(II) ion, occupied possibly by a stereoactive lone pair on lead(II). The coordination around lead atoms is hemidirected. The parallel aromatic rings in Pb(tpy)(CH3COO)2 show π − π stacking.

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