Zobrazeno 1 - 10
of 179
pro vyhledávání: '"R. Restori"'
Autor:
Otto Ermer, Eric Blanc, Dieter Schwarzenbach, Paloth Venugopalan, R. Restori, Marcel Förtsch, H.-B. Bürgi
Publikováno v:
Acta Crystallographica Section B Structural Science. 56:1003-1010
In the compound [C6H6O2]3C60, hydroquinone (C6H6O2) forms a three-dimensional hydrogen-bonded network enclosing roughly spherical cages with point symmetry \overline 3m and a diameter of 13.2 Å at 100 K. Although C60 fits tightly into these cages, i
Autor:
Dieter Schwarzenbach, R. Restori
Publikováno v:
Acta Crystallographica Section A Foundations of Crystallography. 52:369-378
Anharmonic and electron-density ref'mements against accurate X-ray diffraction data are today almost routine. However, the unambiguous identification and separation of effects due to anharmonic atomic motion and to chemical bonding is impossible with
Publikováno v:
Europhysics Letters (EPL). 33:205-210
Pure C70 crystallizes in close-packed crystal structures. Both the hexagonal close packing (h.c.p.) and the cubic close packing (c.c.p.) are known to exist. X-ray diffraction from single crystals with hexagonal habitus shows rods of diffuse intensity
Publikováno v:
Europhysics Letters (EPL). 27:359-364
The room temperature structure of the hexagonal family of modifications of pure C70 has been studied by single-crystal X-ray diffraction. The experimental evidence indicates rotational symmetry of the molecular electron density and supports the previ
Autor:
Alan L. Balch, R. Restori, Bruce C. Noll, Joong W. Lee, H. B. Buergi, D. Schwarzenbach, Marilyn M. Olmstead
Publikováno v:
Chemistry of Materials. 6:1325-1329
Publikováno v:
Acta Crystallographica Section B Structural Science. 49:832-838
Using published synchrotron X-ray data, the room-temperature scattering density distribution of pure C 60 has been parametrized in terms of a combination of eight oriented symmetry-related images of the molecule, and of a freely spinning molecule. Co
Autor:
Dieter Schwarzenbach, R. Restori
Publikováno v:
Zeitschrift für Naturforschung A. 48:12-20
X-ray diffraction data in heavy-atom compounds may be sensitive to anharmonic atomic displacements, since the large core electron densities result in appreciable scattering amplitudes at large reciprocal distances. Since bonding electron densities ma
Publikováno v:
Ferroelectrics. 108:165-170
Single-crystal neutron-diffraction studies of PbTiO3, in its tetragonal (ferroelectric) phase at room temperature, at Tc - 60 K and at Tc - 20 K, and in its cubic phase at Tc+ 2 K, Tc + 50 K and Tc + 100 K, give evidence that the phase transition, at
Autor:
R. Restori
Publikováno v:
Chemical Physics. 143:57-66
It is shown that the apparently singular zero-term of the Fourier series expansion of the electrostatic potential in a crystal is in fact finite and well defined. Analytical expressions for this term are given for the free-atom model of a crystal and
Autor:
R. Restori, D. Schwarzenbach
Publikováno v:
Acta Crystallographica Section B Structural Science. 51:261-263
The thermally smeared electron density in K 2 PtCl 6 at room temperature is determined from accurate high-resolution X-ray data with the method of maximum entropy. Results are presented in the form of difference-density maps. In an earlier study, the