Zur Kenntnis des Argyrodit-Strukturtyps: Die Kristallstruktur von Ag8SiS6 / The Argyrodite Structure Type : The Crystal Structure of Ag8SiS6

1977 ◽  
Vol 32 (4) ◽  
pp. 373-379 ◽  
Author(s):  
Bernt Krebs ◽  
Jürgen Mandt
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Room Temperature ◽  
Structure Type ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Temperature Modification ◽  
Face Centered ◽  
Temperature Factors ◽  
High Temperature Modification

The room temperature modification of Ag8SiS6 is orthorhombic, space group Pna21, with α = 15.024, b = 7.428, c = 10.533 Å, Z = 4. A complete single crystal X-ray structure analysis shows the structure to contain tetrahedral SiS4(4-) units (Si-S 2.094(12) ... 2.130(12) Å) besides isolated sulfide groups coordinated by Ag; the compound may thus be formulated as Ag8(SiS4)(S)2. The coordination of the Ag atoms by sulfur is distorted tetrahedral (Ag-S 2.557...2.757 A), approximately trigonal planar (Ag-S 2.386...2.775 A, with one additional weakly bonded axial S at 2.991 ... 3.330 Å), or linear (Ag-S 2.414... 2.443 Å). Within the (ordered) Ag sublattice the temperature factors are significantly higher than for Si and S, indicating a certain mobility of the Ag atoms. The arrangement of the thiosilicate -sulfide part of the structure is pseudocubic face-centered, showing the close structural relationship to the disordered cubic high temperature modification of Ag8GeTe6.

Crystal structure and powder diffraction pattern of high-temperature modification of Pd73Sn14Te13

2007 ◽  
Vol 22 (4) ◽  
pp. 334-339 ◽  
Author(s):  
F. Laufek ◽  
A. Vymazalová ◽  
J. Plášil
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Title Compound ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Temperature Modification ◽  
High Temperature Modification

Crystal structure of high-temperature modification of Pd73Sn14Te13 has been refined by the Rietveld method from laboratory X-ray powder diffraction data. Refined crystallographic data of Pd73Sn14Te13 are a=7.6456(3) Å, c=13.9575(9) Å, V=706.75(6) Å3, space group P63cm (No. 185), Z=6, and Dx=10.71 g/cm3. The title compound is isostructural with Pd5Sb2 and Ni5As2; it can be considered as a stacking and filling variant of the Ni2In structure. An important structural feature in the high-temperature modification of Pd73Sn14Te13 is the presence of various Pd-Pd bonds.

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