James A. Ibers

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Single-crystal x-ray diffraction methods were used to determine the crystal and molecular structure of C(60) buckminsterfullerene. At 110 kelvin C(60) is cubic, apparent Laue symmetry m3m, but it exhibits noncrystallographic systematic extinctions indicative of a twin in which I(hkl) and I(khl) are superimposed. In fact, C(60) crystallizes with four(More)
The compounds ThOS, ThOSe, and ThOTe have been synthesized, and their structures have been determined by means of single-crystal X-ray diffraction methods. All three compounds adopt the PbFCl structure type in the tetragonal space group D(4h)(7) - P4/nmm. More precise crystallographic data have been obtained for ThOS and ThOSe, which had previously only(More)
Single crystals of CsU(2)Te(6) were synthesized from the reaction of U, Te, and Cs(2)Te(3) at 1273 K. CsU(2)Te(6) crystallizes in the space group Cmcm in the CsTh(2)Te(6) structure type. The asymmetric unit comprises one U (site symmetry m2m), one Cs (m2m; half-occupancy) and two Te atoms (m.. and m2m). The structure of CsU(2)Te(6) consists of infinite(More)
β-UPSe was synthesized from the reaction of U(2)Se(3), P and Se in a CsCl flux in a fused-silica tube. It crystallizes with four formula units in the tetra-gonal space group I4/mmm in the UGeTe structure type. The asymmetric unit comprises one U (site symmetry 4mm), one Se (4mm), and one P (mmm.) atom. The U atom is coordinated in a monocapped(More)
Zirconium(IV) dilanthanum(III) penta-sulfide, ZrLa(2)S(5), crystallizes with four formula units in the space group Pnma in the U(3)S(5) structure type. The asymmetric unit comprises one Zr, one La and four S atoms. The Zr and three S atoms are situated on mirror planes. The structure consists of LaS(8) face-sharing bicapped distorted trigonal prisms and(More)
The title compound, NpCuSe(2), is the first ternary neptunium transition-metal chalcogenide. It was synthesized from the elements at 873 K in an evacuated fused-silica tube. Single crystals were grown by vapor transport with I(2). NpCuSe(2) crystallizes in the LaCuS(2) structure type and can be viewed as a stacking of layers of CuSe(4) tetra-hedra and of(More)
Tetra-yttrium(III) tris-ulfide disilicate, Y(4)S(3)(Si(2)O(7)), crystallizes in the Sm(4)S(3)(Si(2)O(7)) structure type. The structure consists of isolated (Si(2)O(7))(6-) units (2mm. symmetry) and two crystallo-graphically independent Y(3+) cations bridged by one S and one O atom. The first Y atom (site symmetry .m.) is coordinated by three O atoms and(More)
The compounds BaLn(2)Se(4) (Ln = rare-earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe(2)O(4) structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three-dimensional(More)