Structure and bond length distribution in Hf2Fe and Hf2Co intermetallic compounds

1998 ◽  
Vol 84 (9) ◽  
pp. 4842-4846 ◽  
Author(s):  
B. Cekić ◽  
N. Ivanović ◽  
Z. Rakočević ◽  
V. Koteski ◽  
M. Manasijević ◽  
...  
Keyword(s):  
Bond Length ◽  
Intermetallic Compounds ◽  
Length Distribution ◽  
Bond Length Distribution

On the effect of Ga and In substitutions in the Ca11Bi10and Yb11Bi10bismuthides crystallizing in the tetragonal Ho11Ge10structure type

2018 ◽  
Vol 74 (3) ◽  
pp. 269-273 ◽  
Author(s):  
Alexander Ovchinnikov ◽  
Svilen Bobev
Keyword(s):  
Bond Length ◽  
Length Distribution ◽  
Structural Response ◽  
Structure Type ◽  
First Principle ◽  
X Ray Diffraction ◽  
Interatomic Distances ◽  
X Ray ◽  
Type Bond ◽  
Bond Length Distribution

The Ga- and In-substituted bismuthides Ca11GaxBi10–x, Ca11InxBi10–x, Yb11GaxBi10–x, and Yb11InxBi10–x(x< 2) can be readily synthesized employing molten Ga or In metals as fluxes. They crystallize in the tetragonal space groupI4/mmmand adopt the Ho11Ge10structure type (Pearson codetI84; Wyckoff sequencen2m j h2e2d). The structural response to the substitution of Bi with smaller and electron-poorer In or Ga has been studied by single-crystal X-ray diffraction methods for the case of Ca11InxBi10–x[x= 1.73 (2); octabismuth undecacalcium diindium]. The refinements show that the In atoms substitute Bi only at the 8hsite. The refined interatomic distances show an unconventional – for this structure type – bond-length distribution within the anionic sublattice. The latter can be viewed as consisting of isolated Bi3−anions and [In4Bi820−] clusters for the idealized Ca11In2Bi8model. Formal electron counting and first-principle calculations show that the peculiar bonding in this compound drives the system toward an electron-precise state, thereby stabilizing the observed bond-length pattern.

scholarly journals Redetermination of β-Ba(PO3)2

2014 ◽  
Vol 70 (2) ◽  
pp. i7-i7 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Bond Length ◽  
Coordination Polyhedron ◽  
Structure Determination ◽  
Length Distribution ◽  
Anisotropic Displacement Parameters ◽  
The Absolute ◽  
Bond Length Distribution ◽  
Absolute Structure ◽  
Atomic Coordinates

In comparison with the previous structure determination of the β-modification of bariumcatena-polyphosphate that was based on Weissenberg film data [Grenieret al.(1967).Bull. Soc. Fr. Minéral. Cristallogr.90, 24–31], the current CCD-data-based redetermination reveals all atoms with anisotropic displacement parameters, standard uncertainties for the atomic coordinates, and the determination of the absolute structure. Moreover, a much higher accuracy in terms of the bond-length distribution for the polyphosphate chain, with two shorter and two longer P—O distances, was achieved. The structure consists of polyphosphate chains extending parallel to [100] with a periodicity of two PO4tetrahedra. The Ba2+cations are located between the chains and are surrounded by ten O atoms in the form of a distorted coordination polyhedron, with Ba—O distances ranging from 2.765 (3) to 3.143 (3) Å, also reflecting the higher precision of the current redetermination.

scholarly journals Crystal structure oftrans-1,4-bis[(trimethylsilyl)oxy]cyclohexa-2,5-diene-1,4-dicarbonitrile

2014 ◽  
Vol 70 (8) ◽  
pp. 77-79 ◽  
Author(s):  
Florian Glöcklhofer ◽  
Johannes Fröhlich ◽  
Berthold Stöger ◽  
Matthias Weil
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Title Compound ◽  
Length Distribution ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
Compound C ◽  
Tetrahedral Angle ◽  
Bond Length Distribution ◽  
Single Bonds

The asymmetric unit of the title compound, C14H22N2O2Si2, contains one half of the molecule, which is completed by inversion symmetry. The cyclohexa-2,5-diene ring is exactly planar and reflects the bond-length distribution of a pair of located double bonds [1.3224 (14) Å] and two pairs of single bonds [1.5121 (13) and 1.5073 (14) Å]. The tetrahedral angle between thesp3-C atom and the two neighbouringsp2-C atoms in the cyclohexa-2,5-diene ring is enlarged by about 3°.

Effect of Nd content on the energetics of H2O adsorption and defect structure in the Ce(1−x)NdxO(2−0.5x) system

2020 ◽  
Vol 8 (41) ◽  
pp. 21842-21851
Author(s):  
Y. Mordekovitz ◽  
S. Sagi ◽  
S. Barzilai ◽  
S. Hayun
Keyword(s):  
Bond Length ◽  
Defect Structure ◽  
Length Distribution ◽  
Excess Adsorption ◽  
Adsorption Enthalpy ◽  
System P ◽  
Bond Length Distribution

The effect of Nd on the bond length distribution and excess adsorption enthalpy of H2O (relative to pure CeO2) in the Ce(1−x)NdxO(2−0.5x) system.

On measuring the size of distortions in coordination polyhedra

2006 ◽  
Vol 62 (4) ◽  
pp. 692-694 ◽  
Author(s):  
I. David Brown
Keyword(s):  
Bond Length ◽  
Coordination Polyhedron ◽  
Length Distribution ◽  
Higher Moments ◽  
Coordination Polyhedra ◽  
The Third ◽  
Suitable Index ◽  
Average Bond ◽  
Bond Length Distribution ◽  
Unique Index

There is no unique index that measures the size of the distortion found in a coordination polyhedron because different indices can result in a different ordering depending on the mode of the distortion (i.e. the third and higher moments of the bond-length distribution). This paper proposes the increase in the average bond length as a suitable index as this is directly related to the increase in volume of the coordination polyhedron and hence of the unit cell. Some examples are discussed.

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