Die Kristallstruktur von Si5O[PO4]6

The crystal structure of Si₅O[PO₄]₆ has been determined and refined by least-squares, using three-dimensional X-raydata fromWeissenberg photographs: space group R 3;a=7.86₉ andc=24.13₈ Å;Z=3; 418 independent reflections;R=6.0%. The crystal structure consists of isolated [SiO₆] octahedra and [Si₂O₇] groups which are linked by [PO₄] tetrahedra forming a three-dimensional network. The average interatomic distances are: Si[6]?O=1.76₈, Si[4]?O=1.60₇ and P?O=1.52_i Å. The compound is isotypic with Ge₅O[PO₄]₆.     

Die Kristallstruktur von Ir4Ge5

Zusammenfassung Mittels Fourier- und Differenz-Fourier-Synthesen wird eine Struktur für Ir₄Ge₅ errechnet. Der Aufbau, der einem Abkömmling des TiSi₂-Typs mit starkem Unterschuß desB-Elements entspricht, ist durch Stapelung in Richtung derc-Achse gemäßn=4 charakterisiert.

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By means of Fourier- and difference Fourier-synthesis a crystal structure for Ir₄Ge₅ was calculated. The crystal structure of Ir₄Ge₅, a derivative of the TiSi₂-type structure with a strong deficiency of theB-element, is characterized by a 4-fold stacking of the subcell in thec-direction.

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Herrn Professor Dr.J. W. Breitenbach zum 60. Geburtstag gewidmet.     

Die Kristallstruktur der Verbindung LiNa[Ge4O9]

Zusammenfassung Die Kristallstruktur der Verbindung LiNa[Ge₄O₉] wird durch dreidimensionale Patterson- und Fourier-Synthesen bestimmt und mit Hilfe der Methode der kleinsten Quadrate verfeinert. Die rhombische Elementarzelle (Pcca-D _2h ⁸ ) mit den Abmessungen:a=9,31,b=4,68,c=15,88 Å enthält 4 Formeleinheiten. Die Struktur wird aus [GeO₃] _n -Ketten mit tetraedrisch koordiniertem Germanium aufgebaut, die über [GeO₆]-Oktaeder zu einem dreidimensionalen Gerüst vernetzt sind. Als mittlere interatomare Ge-O-Abstände wurden erhalten: 1,758 [4] und 1,866[6] Å. Die Verbindung LiNa[Ge₄O₉] stellt ein Endglied der Mischreihe Li_2–x Na _x [Ge₄O₉] dar.

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Crystal structure of LiNa[Ge₄O₉]

The crystal structure of LiNa[Ge₄O₉] has been determined by means of three-dimensional Patterson and electron density syntheses and refined by least-squares methods. The orthorhombic unit cell (Pcca-D _2h ⁸ ) having the lattice parametersa=9.31,b=4.68 andc=15.88 Å contains 4 formula units. The crystal structure consists of [GeO₃] _n -chains of tetrahedrally coordinated Ge-atoms which are connected by [GeO₆]-octahedra to form a three-dimensional framework. The interatomic Ge-O-distances are found to be 1.758[4] and 1.866[6] Å. The compound LiNa[Ge₄O₉] represents a member of the solid solution series Li_2–x Na _x [Ge₄O₉].

     

Die Kristallstruktur des Lithium-enneagermanats Li4[Ge9O20]

The crystal structure of lithium enneagermanate, Li₄[Ge₉O₂₀], has been determined and refined by least-squares, using three-dimensional single-crystal data. The compounds crystallizes with monoclinic symmetry (a=12.43,b=8.00,c=7.49 Å, =91.0^o; C2–C₂ ³) building up a framework structure which exhibits some similarity with the structures of Li₂[Ge₄O₉] and Li₂[Ge₇O₁₅]. Out of the 18 Ge-atoms in the unit cell 14 are surrounded tetrahedrally by oxygen showing an average distance of 1.757 Å; the remaining 4 Ge-atoms are octahedrally coordinated with an average distance of 1.886 Å.

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Die Kristallstruktur des Lithium-enneagermanats Li₄[Ge₉O₂₀]

Zusammenfassung Die Kristallstruktur von Lithium-enneagermanat Li₄[Ge₉O₂₀] wird an Hand dreidimensionaler Einkristalldaten ermittelt und nach der Methode der kleinsten Quadrate verfeinert (R=0,083). Die monoklin kristallisierende Verbindung (a=12,43;b=8,00;c=7,49 Å; =91,0^o; C2–C₂ ³) besitzt eine Gerüstruktur, die einen ähnlichen Aufbau wie Li₂[Ge₄O₉] und Li₂[Ge₇O₁₅] zeigt. Von den 18 Ge-Atomen in der Elementarzelle liegen 14 in tetraedrischer Koordination mit einem mittleren Ge–O-Abstand von 1,757 Å vor; 4 Ge-Atome sind oktaedrisch umgeben, mit einem mittleren Ge–O-Abstand von 1, 1886 Å.

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Herrn Professor Dr.O. Hromatka zum 65. Geburtstag gewidmet.     

Die Kristallstruktur von AgIIF[AgIIIF4]

Crystal structure of Ag^IIF[Ag^IIIF4] For the first time dark brown single crystals of mixedvalent AgF[AgF₄] were isolated under solvothermal conditions out of anhydrous HF/F₂. The compound crystallizes in a new type of structure, triclinic with a = 499.9(2) pm, b = 1108.7(5) pm, c = 735.7(3) pm, α = 90.05(3)°, β = 106.54(4)°, γ = 90.18(4)°, spcgr. P1¯ — C_i¹ (No. 2) and Z = 4.     

Die Kristallstruktur von CsTcO4 [1]

The Crystal Structure of CsTcO₄ CsTcO₄ crystallizes orthorhombic with a = 5.72₇, b = 5.92₁ and c = 14.34 Å. Z = 4, space group Pnma (Nr. 62, I.T.). The metal positions were refined by single crystal data, the oxygen positions first determined: the CsTcO₄ structure is a slight distortion of the scheelite arrangement (parameters: see text). The MADELUNG Part of Lattice Energy, MAPLE, ?Mean Effective Ionic Radii”?, MEIR, and Effective Coordination Numbers, ECoN, are calculated and discussed.     

Die Kristallstruktur des Tetragermanats K2Ba[Ge4O9]2

The crystal structure of the compound K₂Ba[Ge₄O₉]₂ has been determined by means of three-dimensional X-ray data resulting a finalR-value of 0.034. The lattice constants of the trigonal unit cell ( ) are:a=11.729 (I) andc=19.278 (3) Å. There is a close structural relationship to the tetragermanates K₂Ge₄O₉ and BaGe₄O₉. The new compound also consists of three-membered rings built up by [GeO₄] tetrahedra, which are linked by [GeO₆] octahedra forming a three-dimensional network.According to their powder diagrams the following compounds are isostructural to K₂Ba[Ge₄O₉]₂: Na₂Ba[Ge₄O₉]₂, Rb₂Ba[Ge₄O₉]₂, Na₂Sr[Ge₄O₉]₂ and K₂Sr[Ge₄O₉]₂.     

Die Verfeinerung der Kristallstruktur von Li2Ge2O5

Zusammenfassung Die Kristallstruktur von Li₂Ge₂O₅ wird durchFourier- und Differenz-Fourier-Synthesen verfeinert. Als mittlere Atomabstände werden gefunden: Ge–O=1,71 und Li–O=1,96 Å.

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The crystal structure of Li₂Ge₂O₅ has been refined byFourier and difference syntheses. The average atomic distances are found to be: Ge–O=1,71 and Li–O=1,96 Å.

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Die Kristallstruktur von Na4CoO4[1]

The Crystal Structure of Na₄CoO₄ According to X-Ray investigations on single crystals, Na₄CoO₄ crystallizes triclinic (P1, a = 8.64₈, b = 5.70₂, c = 6.40₀ Å, α = 123.9°, β = 98.1°, γ = 99.2°). There are almost tetrahedral CoO₄-groups; sodium is coordinated by four or five O^2?.     

Die Kristallstruktur des Lithiumheptagermanats Li2[Ge7O15]

Zusammenfassung Die Kristallstruktur der Verbindung Li₂[Ge₇O₁₅] wird mit Hilfe dreidimensionaler Patterson- und Fourier-Synthesen bestimmt und nach der Methode der kleinsten Quadrate verfeinert. Die Gitterparameter der orthorhombischen Elementarzelle (Pbcn — D _2h ¹⁴ ) betragen:a=7,36,b=16,76 undc=9,69 Å. Die Struktur enthält stark gewellte Schichten aus [GeO₄]-Tetraedern, die über [GeO₆]-Oktaeder zu einem dreidimensionalen Gerüst verknüpft sind; sie läßt sich durch die Formel Li₂[Ge(Ge₂O₅)₃] charakterisieren. Als mittlere Ge–O-Abstände werden erhalten: 1,735 Å (K.Z. 4) und 1,893 Å (K.Z. 6).

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The crystal structure of Li₂[Ge₇O₁₅]

The crystal structure of Li₂[Ge₇O₁₅] has been determined by means of three-dimensional Patterson and electron density syntheses, and refined by least-squares method. The lattice parameters of the orthorhombic unit cell (Pbcn-D _2h ¹⁴ ) are:a=7.36,b=16.76 andc=9.69 Å. The crystal structure contains strongly puckered layers of [GeO₄]-tetrahedra linked by [GeO₆]-octahedra to form a three-dimensional framework; the structure can be characterized by the formula Li₂[Ge(Ge₂O₅)₃]. The averaged Ge–O-distances are found to be: 1.735 Å (c. n. 4) and 1.893 Å (c.n. 6).

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Die Kristallstruktur von Antimontetrachlorid-cyanurat [SbCl4NCO]3

The Crystal Structure of Antimony Tetrachloride Cyanurate [SbCl₄NCO]₃ [SbCl₄NCO]₃ crystallizes in the hexagonal space group P6₃/m with two formula units per unit cell; the lattice parameters are a = 1167 and c = 995 pm. The crystal structure was solved with X-ray diffraction data by means of a Patterson and a Fourier Synthesis and was refined by the method of least-squares to a reliability index of R = 3.6% for the 863 observed reflexions. The structure consists of [SbCl₄NCO]₃ molecules having the point symmetry 6 . The molecule is a derivate of cyanuric acid in a way such that each Sb atom is bonded in chelate manner by one N and one O atom; together with 4 Cl atoms the antimony attains a distorted octahedral coordination. The packing density in the crystal is not optimal, there exist cavities.     

Die Kristallstruktur von Perowskiten ANiIIMVIO6. I. Das Sr2[NiTe]O6

The structure of the perovskite compound Sr Ni^IITe^{VI (6)}O₆ (1:1 order in the octahedral sites) is described in detail. The obtained Ni? O distance (2.04 Å a_Te–O = 1.91 Å) together with that one within the corresponding tungsten perovskite (part II) will be analyzed quantitatively with respect to the connection between structure and ligand-field as well as EPR data. The comparison of this distance and the spectroscopic results of the tellurium perovskite with corresponding data of Ni^II-doped MgO however shows already now that an interpretation on the basis of an ionic model is impossible     

Die Kristallstruktur von LiEu3O4

The crystal structure of LiEu₃O₄ which represents a new structure type was solved by usual methods with the aid of integrated WEISSENBERG photographs (MoK_α radiation, 787 reflexions) and refined to a reliability index of 4.3%. In LiEu₃O₄ just as in the first known europium(II, III)-oxide, Eu₃O₄, a clear distinction is possible between the divalent and trivalent europium ions. The given assignment which is based on crystal chemical arguments has been verified indirectly by means of the isostructural compound LiSr₂EuO₄, the cation distribution of which was established experimentally. The structure of LiEu₃O₄ is discussed in connection with the related oxides EuO and Eu₃O₄. The geometrical relations to the latter are of special interest, as LiEu₃O₄ undergoes a topotactical transformation into Eu₃O₄ by heating it in a high vacuum. There is an astonishing close structural relationship between LiEu₃O₄ and Yb₃S₄: except for lithium all the atoms are correlated as for isostructural compounds.     

Die Kristallstruktur des Lithiumdigermanats Li2Ge2O5

The compound Li₂Ge₂O₅ has been prepared by annealing a glassy melt (500° C). The lattice parameters have been determined from single crystal photographs:a=5,99,b=15,19,c=4,97 Å and β=90,0°, space group C _S ⁴ :?Cc. Li₂Ge₂O₅ has a layer structure and is isostructural with Li₂Si₂O₅.     

Darstellung und Kristallstruktur von K6[Al2O6] und Rb6[Al2O6]

Preparation of Crystal Structure of K₆[Al₂O₆] and Rb₆[Al₂O₆] Colourless single crystals of K₆[Al₂O₆] have been prepared from intimate mixtures of KAlO₂ and K₂O (550°C, 90 d). The structure determination from four-circle diffractometer data (MoKα , 742 I_o(hkl), R = 2.2%, R_w = 2.1%) confirms the space group C2/m with Z = 2; a = 698.25 pm, b = 1 103.54 pm, c = 646.49 pm, β = 102.49°. Colourless single crystals of hitherto unknown Rb₆[Al₂O₆] have been prepared from intimate mixtures of RbAlO₂ and Rb₂O (520°C, 120 d). The structure determination from four-circle diffractometer data (MoKα , 1 240 I_o(hkl)) results in the residual values R = 7.2%, R_w = 4.9%; space group C2/m; a = 725.92 pm, b = 1 143.33 pm, c = 678.06 pm, β = 104.05°; Z = 2. K₆[Al₂O₆] and Rb₆[Al₂O₆] are isostructural with K₆[Fe₂O₆]. A characteristic structure unit is the anion [Al₂O₆]^6? consisting of two edge-sharing [AlO₄] tetrahedra. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), the Madelung Part of Lattice Energy (MAPLE) and the Charge Distribution (CHARDI) are calculated and discussed.     

Die Kristallstruktur der Verbindung Li6[Si2O7]

Zusammenfassung Die Kristallstruktur von Li₆[Si₂O₇] wird mit Hilfe von Patterson-Projektionen und dreidimensionalen Fourier-Synthesen sowie nach der Methode der kleinsten Quadrate bestimmt. Die Gitterparameter der tetragonalen Elementarzelle (P42₁m-D _2d ³ ) betragen:a=7,71₅;c=4,88 Å. Die Verbindung zählt zu den Sorosilicaten mit isolierten [Si₂O₇]-Gruppen. Die Lithiumionen weisen gegenüber Sauerstoff die Koordinationszahlen 4 und 5 auf. Als mittlere Abstände [Å] wurden ermittelt: Si-O : 1,64 Li-O : 1,95 [4] und 2,18 [5].

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The crystal structure ofLi ₆[Si ₂ O ₇]

The crystal structure of Li₆[Si₂O₇] has been determined by means of Patterson projections, 3-dimensional Fourier syntheses and the least-squares method. The lattice parameters of the tetragonal unit cell (P42₁m-D _2d ³ ) area=7.71₅ andc=4.88 Å. The compound belongs to the sorosilicates having isolated [Si₂O₇]-groups. The coordination numbers of the lithium ions are 4 and 5. The average interatomic distances were found to be: Si-O : 1,64 Å; Li-O : 1.95 [4] and 2.18 [5] Å.

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Die Kristallstruktur von Ag2Ge2O5: Eine neuartige Gerüststruktur von Ge2O52−

Crystal Structure of Ag₂Ge₂O₅: A New Ge₂O₅^2? Network Structure Ag₂Ge₂O₅ was prepared from the binary oxides at high O₂ pressures. Single crystal X-ray diffraction work indicated monoclinic symmetry (P2₁/c; a = 1101.3(2); b = 1006.3(1); c = 1221.9(3) pm; ß = 94.6(1)°). The structure was determined by direct methods (3372 independent structure factors) and refined to a conventional R value of 0.084. A new Ge₂O₅^2? network structure was found with germanium coordinated octahedrally (­d(Ge—O) = 188,7 pm) and tetrahedrally (­d(Ge—O) = 175,9 pm), in equal proportions, by oxygen. The polyhedra share vertices and edges, thus forming a three dimensional channel system, which is occupied by Ag⁺ ions. The shortest Ag—Ag distance of 284 pm, like the pale yellow colour of the compound, indicates Ag⁺—Ag⁺ interaction.     

Die Kristallstruktur von [Cl3PNPCl3][VOCl4]

Investigations on Electronically Conducting Oxide Systems. XIV. Solid Solutions and Conductivity in the System MgTiO₃? Ti₂O₃ Solid solution formation and conductivity is reported for the system Mg_1?xTiTiO₃ (0 < x < 1). Ti^III atoms are predominantly substituted in pairs for Mg^II and Ti^IV. In the range of low x values Ti^III? Ti^III bonds typical for Ti₂O₃ in the semiconducting state are very weakened because of the distances preserved in the host lattice of MgTiO₃. Up to x = 0,5 EPR measurements at 77 K indicate magnetic “dimers” with S = 1 at a distance of 550 pm resulting from antiparallel spin orientation of the Ti^III pairs and transfer of the magnetic interaction by super exchange to a next-neighboured Ti^III pair. Electrical conductivity is caused by polaron hopping. The steep increase in the range of small Ti^III concentration is interpreted by a screening field approximation.     

Die Kristallstruktur von Ru2Ge3

The crystal structure of Ru₂Ge₃ has been determined and refined by Fourier synthesis using pseudo-tetragonal X-ray data resulting from twinned crystals. The true symmetry is orthorhombic with space group Pnca-D _2h ¹⁴ and the lattice parameters are:a=5.718,b=11.436 andc-9.240 Å. Ru₂Ge₃ is a member of the Mn₁₁Si₁₉ structure family which is characterized by the occurrence of different compositions in the rangeTB _2?x (x≤0.75,T=transition metal andB=group III or IV metal). The compounds Ru₂Si₃, Os₂Si₃, Os₂Ge₃, and Ir₂(Ga_0.6Ge_0.4)₃ are isostructural.     

Die Kristallstruktur des Hexakaliumdigermanats,K6Ge2O7

The title compound is monoclinic, space group Pc (No. 7),a=6.549 (1),b=9.094 (1),c=11.426 (2) Å, =126.78 (1)° andZ=2. Its crystal structure has been refined from 1 323 single crystal X-ray reflections toR=0.131. The structure of K₆Ge₂O₇ is very similar to that of K₆Co₂O₇ and K₆Si₂O₇ both of which have been reported to be centrosymmetric, space group P2₁/c. While the angle at the bridging oxygen atom is 180° in the latter compounds, it is 157° in K₆Ge₂O₇.