Die Kristallstruktur von Li2SnO3

Li₂SnO₃ crystallises monoclinic, C, with a = 5.295, b = 9.184, c = 10.032 Å and β = 100.13°; Z = 8. The positions of Sn were obtained from PATTERSON maps and the positions of O and Li by FOURIER difference method. Parameters were refined by least squares-method [1462 reflexes (h 01)–(h 71); R = 10.5%]. The average distances of Li? O are 2.07 Å, and 2.20 Å for Sn? O. The Li₂SnO₃ structure can be derived from the NaCl type: in a cubic closest packing of oxygen 2/3 of the octahedral holes are occupied by lithium and 1/3 by tin.     

Die Kristallstruktur von Li8PbO6

Crystal Structure of Li₈PbO₆ The crystal structure of Li₈PbO₆ (Li₈TbO₆ structure, space group R3 ? C, hexagonal lattice constants a = 554.3, c = 1 563 pm) has been refined by profile analysis of a neutron diffraction pattern. Deviations from ideal tetrahedral and octahedral coordination of lithium atoms are similar to those described for Li₈SnO₆.     

Die Kristallstruktur von Li2TeO3

Crystal Structure of Li₂TeO₃ Crystals of Li₂TeO₃ were prepared from melts. Li₂TeO₃ crystallizes in the monoclinic system, space group C2/c. The lattice parameters are a = 5.06₉, b = 9.56₆, c = 13.72₇ Å, β = 95.4°. The formular unit is 8. The crystal structure has been determined by Patterson and threedimensional differential Fourier synthesis refined by least squares using isotropic temperature corrections. The final R-value of 772 observed reflections is 0.101. Li₂TeO₃ forms a layer lattice consisting of trigonal TeO₃ pyramids and deformed LiO₄ tetrahedrons. The TeO₃ pyramids are only connected with the corners of LiO₄ groups, which are linked one with another by common corners and edges.     

Die Kristallstruktur von Li2GeO3

Zusammenfassung Die Kristallstruktur von Li₂GeO₃ wird mit Hilfe dreidimensionalerFourier-Synthesen und nach der Methode der kleinsten Quadrate bestimmt. Li₂GeO₃ ist isotyp mit Li₂SiO₃ und enthält [GeO₃]^2–-Ketten (Zweiereinfachkette). Die Gitterparameter der rhombischen Elementarzelle (C _2v ¹² –Cmc2₁) betragen:a=9,63₀,b=5,46₅ undc=4,85₀ Å. Als mittlere interatomare Abstände wurden erhalten: Ge–O=1,74 und Li–O=2,01 Å.

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The crystal structure of Li₂GeO₃ has been determined by means of 3-dimensional Fourier syntheses and least-squares method. Li₂GeO₃ is isostructural with Li₂SiO₃, containing [GeO₃]^2–-chains (Zweiereinfachkette). The lattice parameters of the orthorhombic cell (C _2v ¹² –Cmc2₁) are:a=9,63₀;b=5,46₅ andc=4,85₀ Å. The average interatomic distances are found to be: Ge–O=1,74 and Li–O=2,01 Å.

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Die Kristallstruktur der Verbindung Li2ZnGeO4

The crystal structure of dilithiumzine orthogermanate, Li₂ZnGeO₄, has been determined and refined byFourier syntheses and least-squares, using three dimensional single-crystal data. A finalR-value of 5.7% was obtained. The monoclinic unit cell (Pn–C_s ²) with the dimensionsa=6.40,b=5.45,c=5.04 Å and =90.2° contains two formula units Li₂ZnGeO₄. The crystal structure is built up by [GeO₄] tetrahedra, which are linked together by [LiO₄] and [ZnO₄] tetrahedra. The average interatomic distances are found to be: Ge–O=1.77, Li–O=2.01 and Zn–O=1.93 Å.     

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 von Lithiummetaperiodat,LiIO4

The Crystal Structure of Lithiummetaperiodate, LiIO₄ For the first time single crystals of LiIO₄ were obtained. According to the results of an X-ray structure determination (monoclinic, P2₁/n; a = 525.5(3), b = 851.1(4), c = 796.9(5) pm, β = 104.21(3)°; Z = 4; 2 148 diffractometer data, R = 0.024) the coordination by oxygen is tetrahedral for iodine and strongly distorted trigonal bipyramidal for lithium. Two lithium-oxygen-polyhedra are connected via a common edge. LiIO₄ crystallises isostructural to LiAlH₄. The structure is discussed and compared to those of other metaperiodates and tetrahydridoaluminates.     

Die Kristallstruktur von Diäthylamino-titantrichlorid

Diethylaminotitanium trichloride, (C₂H₅)₂NTiCl₃, is monoclinic with space group P2₁/n and a = 6.131 Å; b = 12.290 Å; c = 12.081 Å and β = 87.20°. There are four formula units per unit cell. The structure analysis with three-dimensional diffractometer data yielded an R-factor of 0.079 for 1509 observed reflexions. The titanium atom has coordination number six. The NTiCl₅ octahedra are linked into infinite zig-zag chains by sharing Cl? Cl edges. The nitrogen atom and one chlorine atom do not participate in bridging. The Ti? N distance at 1.852 Å is significantly shorter than a hypothetical pure single bond.     

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 von Nb5Cu4Si4

Zusammenfassung Die Struktur von Nb₅Cu₄Si₄ wird mit Hilfe von Einkristallmethoden bestimmt und verfeinert. Die Abmessungen der tetragonalen, innenzentrierten Elementarzelle sind:a=10,1908 undc=3,6004 Å. Die Zelle beinhaltet 2 Formeleinheiten, die Raumgruppe ist C _4h ⁵ –I4/m.

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The crystal structure of Nb₅Cu₄Si₄ has been determined and refined by single-crystal X-ray methods. The cell dimensions of the tetragonal body-centered unit cell are found to be:a=10,1908 andc=3,6004Å. The cell content is 2 formula units, the space group is C _4h ⁵ –I4/m.

     

Reindarstellung und Kristallstruktur von Lithiumnitridhydrid,Li4NH,Li4ND

Preparation and Crystal Structure of Lithium Nitride Hydride, Li₄NH, Li₄ND Single phase Li₄NH was prepared by the reaction of Li₃N and LiH at 490°C. Its structure has been solved from x-ray and time-of-flight neutron powder diffraction data. Li₄NH crystallizes in an ordered variant of the Li₂O structure. N and H occupy the sites of two interpenetrating “extended” diamond lattices. Li occupies all N₂H₂ tetrahedral voids and is found to be shifted into a N₂H tetrahedral face. As a result H is in compressed tetrahedral coordination by Li, while N is in bisdisphenoidal coordination by Li. Alternatively, the Li₄NH structure may be regarded as a [Li₄N]⁺threedimensional net, its voids being filled up with H^?. Li₄NH is a reactive solid, which decomposes to imide when in contact with N₂ or H₂ at some 400°C.     

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 von 1,4-trans-Cyclohexan-dicarbonsäure

Crystals of 1,4-trans-cyclohexane-dicarboxylic acid are monoclinic, a = 5.60 Å, b = 9.63 Å, c = 8.05 Å, γ = 107°14′, space group P2₁/b (first setting), with 2 centrosymmetric molecules in the unit cell. The structure has been solved by direct methods and refined by full-matrix least-squares analysis of three-dimensional intensity data. The mean CCC-angle in the cyclohexane ring is found 112.0°. The conformation of the carboxylic group in various acids is discussed.     

Die Kristallstruktur von Ammonium-dioxodifluorovanadat

The Crystal Structure of NH₄VO₂F₂ Crystals of NH₄VO₂F₂ are monoclinic, space group Pc, a = 4.814(2), b = 11.434(3), c = 7.214(2) Å, β = 108.84(4)°. Z = 4. The VO₂F-ion is polymeric. The structure consists of endless chains of strongly distorted octahedra with common edges. Two adjacent polyhedra are linked by an asymmetrical oxygen bridge (bond lengths 1.74 and 2.21 Å) and an asymmetrical fluorine bridge (bond lengths 1.97 und 2.21 Å). The terminal V? O- and V? F-distances are 1.55 and 1.86 Å, respectively.     

Die Kristallstruktur von Thalliumtrifluorid

The crystal structure of thallium trifluoride The crystal structure of TlF₃ has been determined form single crystal diffraction data. The unit cell is orthorhombic, space group Pnma≠D, with a = 5.825, b = 7.024, c = 4.851 Å, Z = 4. Each Tl has 8 nearest F-neighbours. The Tl–F distances range from 2.09 to 2.49 Å.     

Die Kristallstruktur von Kaliummonomethylcarbonat

Crystal Structure of Potassium Monomethylcarbonate Potassium monomethylcarbonate KCH₃CO₃ was obtained from reaction of dimethylcarbonate with potassium hydroxide in methanole. The crystal structure was determined (triclinic, P1 (no. 2), Z = 2, a = 380.9(2) pm, b = 558.9(3) pm, c = 985.3(3) pm, α = 100.71(2)°, β = 90.06(3)°, γ = 92.48(3)°, V = 205.9(2) · 10⁶ pm³, wR(F²) = 0.054, wR_obs(F) = 0.022). Structural relations between potassium monomethylcarbonate and potassium hydrogencarbonate are discussed.     

Die Kristallstruktur der Verbindung Li3Zn0,5GeO4

The crystal structure of the compound Li₃Zn_0.5GeO₄ has been determined and refined by means of three-dimensionalFourier syntheses and least squares. Li₃Zn_0.5GeO₄ crystallizes orthorhombic with space groupD _2h ¹⁶ -Pmnb (No. 62) and the lattice parametersa=6.29,b=10.74 andc=5.17 Å. The crystal structure consists of isolated [GeO₄] tetrahedra, which are linked together by [(Li,Zn)O₄] tetrahedra analogous to Li₃PO₄(h). An additional eight-fold position is partly occupied by two lithium atoms. The occupancy of this position may vary according to the observed range of composition, which lies between Li_3.8Zn_0.1GeO₄ and Li_2.6Zn_0.7GeO₄.

     

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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