Zur Kenntnis eines synthetischen Kentrolits/Melanotekits des Indiums: Pb2In2Si2O9 / On an Synthetic Kentrolite/Melanotekite of Indium: Pb2In2Si2O9

1997 ◽  
Vol 52 (10) ◽  
pp. 1213-1218 ◽  
Author(s):  
J.-P. Werner ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Lone Pair ◽  
Lattice Energy ◽  
Orthorhombic Symmetry ◽  
Electronic Polarizability ◽  
Space Group ◽  
Lattice Constants ◽  
Coulomb Term ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of Pb2In2Si2O9 have been prepared by crystallisation from melts of Pb(NO3)2, ln2O3 and SiO2. The compound crystallizes with orthorhombic symmetry, space group C2v9- Pna21 with the lattice constants a = 10.529(1), b = 11.372(1) and c = 7.019(3) Å, Z = 4. Despite the fact that the Kentrolite/Melanotekite structure is characterized by dissimilar occupied split positions of lead, Pb2In2Si2O9 shows completely filled and ordered point positions. The location of a dot like lone pair of Pb2+ is estimated by Coulomb term calculations of lattice energy. The results are discussed with respect to published Pb-lone pair distances using the electronic polarizability coefficient of the lone pair cation or simple geometrical considerations.

Geordnete Metallverteilung in KBaVO4 und KSrVO4 mit β-K2SO4-Struktur / Ordered Metal Distribution in KBaVO4and KSrVO4 Showing β -K2SO4 Structure

1996 ◽  
Vol 51 (4) ◽  
pp. 477-480 ◽  
Author(s):  
O. Schrandt ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Lattice Energy ◽  
Metal Distribution ◽  
Orthorhombic Symmetry ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of KBaVO4(I) and KSrVO4(II) have been prepared by crystallization from V2O5 flux. The yellowish crystals show orthorhombic symmetry, space group D162h-Pnma with (I): a = 7.774(2), b = 5.899(1), c = 10.375(2) Å , (II): a = 7.400(2), b = 5.812(1), c -9.961(1), Z = 4. Both compounds show an ordered distribution of K+ and Ba2+ and Sr2+ respectively. The different sizes of the KO10 and BaO9 (SrO9) polyhedra are discussed with respect to those of the β-K2SO4 structure, considering the calculations of the Coulomb terms of lattice energy.

Isolierte 1∞[TeO5]-Oktaederketten im Bleitellurat Pb2TeO5 / Isolated 1∞[TeO5] Chains of Octahedra in the Lead Tellurate Pb2TeO5

1998 ◽  
Vol 53 (3) ◽  
pp. 287-290 ◽  
Author(s):  
B. Wedel ◽  
L. Wulff ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Lone Pair ◽  
Lattice Energy ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Pb2TeO5 have been prepared by flux techniques. X-ray investigations showed a new crystal structure with monoclinic symmetry, space group C4S -Cc, a = 13.099(3), b = 5.714(1), c = 7.520(2) Å, β = 123,80(3)°, Z = 4. Pb2TeO5 is characterized by 1∞[TeO5] chains of octahedra isolated from each other and incorporated into an edge, corner and face connected frame of PbO7 polyhedra. Possible positions of the lone pair of electrons of Pb2+ are estimated by calculations of Coulomb terms of lattice energy.

scholarly journals Zur Kenntnis eines Barium-Oxoniobat-Tellurats: Ba2Nb2TeO10 / On a Barium-Oxoniobate-Tellurate: Ba2Nb2TeO10

1996 ◽  
Vol 51 (10) ◽  
pp. 1407-1410 ◽  
Author(s):  
B. Wedel ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Orthorhombic Symmetry ◽  
X Ray ◽  
Lattice Constants ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of Ba2Nb2TeO10) have been prepared by solid state reactions in air. X-ray investigations led to orthorhombic symmetry, space group D152h-Pbca, a = 7.242(4), b = 12.433(3), c = 9.932(3) Å. Z = 4. Nb5+ and Te6+ show octahedral coordination by O2- . The crystal structure is characterized by planes of edge- and corner-sharing NbO6- and TeO6octahedra. It is shown that in spite of nearly identical lattice constants of Ba2Nb2TeO10 with compounds of the composition M0,5BaNbTe2O9 the so far unknown crystals of these substances may not be derived from the Ba2Nb2TeO10 type.

Über ein cadmiumreiches Orthovanadat Ba2,5Cd11(VO4)9 mit Cadmium in oktaedrischer und tetragonal pyramidaler Koordination / On a Cadmium Rich Orthovanadate Ba2,5Cd11(VO4)9 Showing Cadmium in Octahedral and Square Pyramidal Coordination

1997 ◽  
Vol 52 (8) ◽  
pp. 989-993 ◽  
Author(s):  
B Mertens ◽  
Hk Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Three Dimensional ◽  
Lattice Energy ◽  
Solid State Reactions ◽  
Orthorhombic Symmetry ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of Ba2,5Cd11(VO4)9 have been prepared by solid state reactions. The new compound crystallizes with orthorhombic symmetry, space group D142h-Pbcn, a = 20.842(6), b = 13.471(3), c = 11.838(9) Å, Z = 4. The crystal structure is characterized and dominated by CdO6 octahedra and unusual square pyramids of O2- around Cd2+ forming a three-dimensional [Cd11O36] network. The interstices are occupied by V5+ and Ba2+ ions. This results in VO4 tetrahedra and irregular BaO10 polyhedra isolated from each other. Occupation of the barium positions is deficient in agreement with the valence state V5+ and calculations of the coulomb terms of lattice energy.

Verknüpfung von (TeO6)6- und (TeO6)3(NiO6)3-Sechsringen durch TeNiO9-Oktaederdoppel in Pb3Ni4,5Te2,5O15 / Connection of (TeO6)6 and (TeO6)3(NiO6)3 Hexagons by TeNiO9 Octahedra Double in Pb3Ni4,5Te2,5O15

1998 ◽  
Vol 53 (5-6) ◽  
pp. 527-531 ◽  
Author(s):  
B. Wedel ◽  
K. Sugiyama ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Lone Pair ◽  
Lattice Energy ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Lattice Constants ◽  
The One ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Pb3Ni4.5Te2.5O15 have been prepared by heating pellets of mixtures of PbO, TeO2 and nickel hydroxide carbonate to 730 °C in air. X-ray investigations led to hexagonal symmetry, space group d66-P6322, lattice constants a = 10.2589(1), c = 13.554(5), Z = 4. Typical features of the crystal structure are face sharing TeNiO9 octahedra doubles and planes of connected (TeO6)6 and (TeO6)3(NiO6)3 hexagons. The one-sided coordination of lead by oxygen is complemented by the lone pair of electrons. The lone pair positions are estimated by calculations of the Coulomb terms of lattice energy.

Isolierte trigonale SrO6 – Prismen verknüpfen Kagome-Netze im Strontium-Manganat(IV)-Tellurat(VI): SrMnTeO6 / Kagomé Layers Connected by Isolated Trigonal SrO6 Prisms in the Strontium Manganate(IV) Tellurate(VI): SrMnTeO6 L

1998 ◽  
Vol 53 (3) ◽  
pp. 283-286 ◽  
Author(s):  
L. Wulff ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Hexagonal Symmetry ◽  
Unknown Compound ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of the hitherto unknown compound SrMnTeO6 have been prepared from Sr(OH)2 ·8H2O , MnCO3(aq) and TeO2 in air by crystallization below the melt range. X-ray investigations showed hexagonal symmetry, space group D33h -P6̅2m, lattice constants a = 5.143( 1), c = 5.384(2) A, Z = 1. SrMnTeO6 is characterized by staggered [(Mn/Te)6O18] Kagome layers along [001]. These layers are connected by Sr2+ ions, resulting in SrO6 prisms isolated from each other. The structure is discussed with respect to the connection of Kagome nets in the quaternary oxides of the Ba3Ln4O9 type.

Zur Synthese und Kristallstruktur von manganhaltigen Boratoxiden: MnFe(BO3)O und MnAl0,5Yo,5(BO3)O / Synthesis and Crystal Structure of Manganese Borate Oxides: MnFe(BO3)O and MnAl0,5Yo,5(BO3)O

1995 ◽  
Vol 50 (8) ◽  
pp. 1146-1150 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Single Crystals ◽  
Orthorhombic Symmetry ◽  
Monoclinic Symmetry ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of the compounds MnFe(BO3)O (I) and MnAl0.5Y0.5(BO3)O (II), were obtained by a B2O3 flux technique. I crystallizes with orthorhombic symmetry, space group D162h -Pnma (Nr.62), a = 939.92; b = 319.41; c = 939.11 pm; Z = 4 and II with monoclinic symmetry, space group C52h-P21/n (Nr. 14). a = 325.6; b = 955.1; c = 929.2 pm; β = 90.70° ; Z = 4. I is isotypic to the mineral Warwickite, while II is a distorded variant of this structure. All metal ions are octahedrally coordinated. Both structures contain isolated, trigonal planar BO3 units and oxygen atoms that are not coordinated to boron.

Zur Kristallchemie des ersten Blei-Zink-Silicium-Telluroxids: PbZn4SiTeO10 / On the Crystal Chemistry of the First Lead Zinc Silicon Tellurium Oxyde PbZn4SiTeO10

1999 ◽  
Vol 54 (4) ◽  
pp. 469-472 ◽  
Author(s):  
B. Wedel ◽  
K. Sugiyama ◽  
K. Hiraga ◽  
K. Itagaki
Keyword(s):  
Negative Charge ◽  
Lattice Energy ◽  
Orthorhombic Symmetry ◽  
X Ray ◽  
Cell Parameters ◽  
Coulomb Term ◽  
Lead Zinc ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of the new lead zinc silicon tellurium oxide PbZn4SiTeO10 have been prepared by solid state reaction in air. The compound is colourless and crystallizes in orthorhombic symmetry, space group D162h Pnma, with the cell parameters: a = 6.542 (5), b = 15.624(4), c = 8.280(4) Å, Z = 4. The structure has been determined from a single crystal X-ray study and refined to the conventional values R = 0.032 and wR(F2) = 0.050. Zn2+ and Si4+ show tetrahedral and Te6+ octahedral coordination by O2-.The crystal structure is dominated by a 3∞ [Zn4O10]12- framework with isolated TeO66+ and SiO44+ polyhedra. Pb2+ ions are incorporated in the network. The centres of negative charge of the lone pairs of Pb2+ are estimated by calculations of the Coulomb term of the lattice energy

Zur Kristallstruktur von ( Cu ,Mn )3,66Mo3O12/On the Crystal Structure of (Cu ,Mn)3,66Mo3O12

1996 ◽  
Vol 51 (3) ◽  
pp. 447-449 ◽  
Author(s):  
O. Sedello ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Orthorhombic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of (Cu,Mn)3.66Mo3O12 have been prepared in sealed copper tubes. X-ray investiga­tions lead to orthorhombic symmetry, space group D2h16-Pnma, a = 5.1541(9), b = 10.788(2), c = 18.114(3)) Å , Z = 4. (Cu,Mn)3.66Mo3O12 is iso­typic to NaCo2.31Mo3O12 and (Cu,Co)3.75Mo3O12 with split positions for two of the metals.

scholarly journals Zur Kristallchemie von CuDyMo2O8 und CuYbMo2O8

1996 ◽  
Vol 51 (2) ◽  
pp. 240-244
Author(s):  
Hk. Müller-Buschbaum ◽  
St. Gallinat
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Rare Earth Ions ◽  
Orthorhombic Symmetry ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
The Rare Earth

Abstract Single crystals of (I) CuDyMo2O8 and (II) CuYbMo2O8 have been prepared by crystalli­sation from melts. Both com pounds crystallize with orthorhombic symmetry, space group D152h-Pbca with (I): a = 10.195(1), b = 9.721(2), c = 14.563(3); (II): a = 10.094(6), b = 9.628(9), c = 14.467(8) Å, Z = 8. The crystal structure is characterized by a triangular CuO3-polygon, a square antiprismatic coordination around the Rare Earth ions and the typical Mo O4 tetra­ hedra.

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