ChemInform Abstract: CRYSTAL STRUCTURE OF 2-LITHIO-2-PHENYL-1,3-DITHIANE-TETRAHYDROFURAN-TETRAMETHYLETHYLENEDIAMINE(1/1/1); “X-X” ELECTRON DENSITY DISTRIBUTION IN LITHIOMETHYL- AND LITHIOPHENYLDITHIANE

1981 ◽  
Vol 12 (38) ◽  
Author(s):  
R. AMSTUTZ ◽  
J. D. DUNITZ ◽  
D. SEEBACH
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution

A study on α-RuCl3 crystal structure by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 30-31
Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Scanning Tunneling Microscopy ◽  
Electron Density ◽  
Structure Determination ◽  
Electron Density Distribution ◽  
Scanning Tunneling ◽  
Monoclinic Space Group ◽  
Tunneling Microscopy ◽  
X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

Electron density distribution and crystal structure of 27R-AlON, Al9O3N7

2013 ◽  
Vol 204 ◽  
pp. 21-26 ◽  
Author(s):  
Toru Asaka ◽  
Hiroki Banno ◽  
Shiro Funahashi ◽  
Naoto Hirosaki ◽  
Koichiro Fukuda
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution

scholarly journals Differenzelektronendichte im gefalteten 2 π-aromatischen System eines 1,3-Dihydro-1,3-diborets / Difference Electron Density in a Folded 2π-Aromatic System of a 1,3-Dihydro-1,3-diborete

1991 ◽  
Vol 46 (12) ◽  
pp. 1621-1624 ◽  
Author(s):  
Hermann Irngartinger ◽  
Jürgen Hauck ◽  
Walter Siebert ◽  
Manfred Hildenbrand
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Ring System ◽  
Membered Ring ◽  
Aromatic System ◽  
Difference Electron Density ◽  
Folding Angle

The crystal structure and the X—X difference electron density distribution of 1,3-bis(diisopropylamino)-1,3,dihydro-1,3-diborete (1) has been determined at the temperature of 107 K. Both π-electrons of the folded aromatic four membered ring system (folding angle 47.6°) are uniformly distributed on the four ring bonds with equal lengths (B—C 1.524 A). These bonds are significantly bent.

Molecular and crystal structure of two phases of 1-fluorosilatrane. Specific features of the electron density distribution

2009 ◽  
Vol 50 (5) ◽  
pp. 873-879 ◽  
Author(s):  
A. A. Korlyukov ◽  
M. Yu. Antipin ◽  
M. I. Buzin ◽  
É. A. Zel’bst ◽  
Yu. I. Bolgova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Molecular And Crystal Structure ◽  
Two Phases

Notizen: Mapping Parts of the Electron Density Distribution from X-Ray Bragg Scattering Intensities (Lambda Technique)

1981 ◽  
Vol 36 (11) ◽  
pp. 1253-1254
Author(s):  
Karl F. Fischer
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Bragg Scattering ◽  
X Ray ◽  
Selection Of

By appropriate selection of two or three wavelengths, intensity differences can be used for obtaining directly the electron density distribution (i.e. the arrangement of atoms) for parts of a crystal structure. Application to macro­molecules and amorphous binary substances appear fea­sible.

Performance of a new furnace for high-resolution synchrotron powder diffraction up to 1900 K: application to determine electron density distribution of the cubic CaTiO3perovskite at 1674 K

2004 ◽  
Vol 37 (5) ◽  
pp. 786-790 ◽  
Author(s):  
Masatomo Yashima ◽  
Masahiko Tanaka
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Density Distribution ◽  
Electron Density ◽  
Structure Analysis ◽  
High Temperatures ◽  
Powder Diffraction ◽  
Electron Density Distribution ◽  
Crystal Structure Analysis ◽  
Synchrotron Powder Diffraction

Accurate crystal structure analysis at high temperatures is an important challenge in science and technology. A new electric furnace for the measurement of high-resolution (δd/d= 0.03%) synchrotron radiation powder diffraction profiles from materials at high temperatures (up to 1900 K in air) has been designed and fabricated. This furnace consists of a ceramic refractory with MoSi2heaters, an aluminium body cooled by flowing water, and a sample stage with a spinner and a controller for sample-height adjustment.In situsynchrotron powder diffraction measurement for a calcium titanate perovskite specimen at 1674 K has been performed using the furnace at beamline 3A of the Photon Factory. The electron density distribution of the cubic perovskite at 1674 K was successfully obtained using a combination of Rietveld refinement, the maximum-entropy method (MEM) and MEM-based pattern-fitting techniques. The Ti atoms exhibit covalent bonding with the O atoms in the cubic CaTiO3perovskite at this temperature, while the Ca atoms are ionic. These results indicate that the new furnace yields high-quality data for accurate crystal structure analysis.

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