74 research outputs found

    Diffraction Symmetry in Crystalline, Close-Packed C60

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    We have grown crystals of the carbon structure C60 by sublimation. In contrast to solution-grown crystals, the sublimed crystals have long range order with no evidence of solvent inclusions. Sublimed C60 forms three dimensional, faceted crystals with a close-packed, face-centered cubic unit cell. We have refined a crystal structure using the "soccer ball" model of the C60 molecule. The results indicate that the C60 molecule has the expected spherical shape, however the data are not sufficiently accurate to unambiguously determine atomic positions

    Pseudotenfold symmetry in pentane-solvated C60 and C70

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    Crystals of C60 or C70 cocrystallized with n-pentane grow as elongated, ten-sided columns. X-ray diffraction shows ordering of C60 or C70 molecules along the column and a remarkable tenfold symmetry normal to the column. The ratio of the x-ray-diffraction vectors of the two lowest-order diffraction spots is nearly equal to the ā€œgolden ratio,ā€ Ļ„. Despite these similarities with decagonal, quasicrystalline order, the diffraction indicates crystalline order with a twinned unit cell

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    Mannitol therapy in perinatal hypoxic-ischemic brain damage in rats.

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