A comparison of the crystal structures of Sb2Tl7, Cu5Zn8 (γ-brass), and Ir3Ge7

1980 ◽  
Vol 58 (7) ◽  
pp. 708-713 ◽  
Author(s):  
Erwin Hellner ◽  
Elke Koch
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Tetrahedral Voids ◽  
Atomic Parameters

The crystal structures of Sb2Tl7, Cu5Zn8, and Ir3Ge7 are discussed with the aid of shortest distances of Dirichlet domains and of voids in their frameworks. It will be pointed out that all three frameworks must be regarded as different though relations between the atomic parameters are obvious. The Sb2Tl7 structure represents a superstructure of an I lattice. The frameworks of Sb2Tl7 and of Cu5Zn8 contain tetrahedral voids only, while in Ir3Ge7 voids with a larger coordination number also exist.

scholarly journals Correction to Benchmarking Coordination Number Prediction Algorithms on Inorganic Crystal Structures

2021 ◽  
Author(s):  
Hillary Pan ◽  
Alex M. Ganose ◽  
Matthew Horton ◽  
Muratahan Aykol ◽  
Kristin Persson ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Prediction Algorithms ◽  
Inorganic Crystal

Organolanthanoids. XI. The Crystal and Molecular Structures of Two Tris(η5-cyclopentadienyl)(pyridine) lanthanoid(III) Compounds

1987 ◽  
Vol 40 (5) ◽  
pp. 907 ◽  
Author(s):  
GB Deacon ◽  
BM Gatehouse ◽  
SN Platts ◽  
DL Wilkinson
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Unit Cell ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Crystal And Molecular Structures

The crystal structures of tris (η5-cyclopentadienyl) (pyridine) samarium(III), monoclinic, space group P21/c, a 10.906(4), b 8.636(2), c 17.825(3) �, β 96.44(2)�, Z 4, R 0.027 and Rw 0.032 for 3619 'observed' reflections, and tris (η5-cyclopentadienyl)(pyridine)neodymium(III), monoclinic, space group P21 / c, a 14-206(4), b 8.619(2), c 15.190(7) �, β 107.38(2)�, Z 4, R 0.035 and R, 0.039 for 2677 'observed' reflections have been determined. Both compounds have pseudotetrahedral geometry with a coordination number of 10 for the lanthanoid metal but there is a difference in the coordination of pyridine and in unit cell packing between the two structures.

Dimere und polymere Pnictidostannat(IV)-Anionen -Darstellung und Kristallstrukturen von Na2K3[SnP3], Na2Cs3[SnP3] und Na2K3[SnBi3] / Dimeric and Polymeric Pnictidostannate(IV) Anions -Preparation and Crystal Structures of Na2K3[SnP3], Na2Cs3[SnP3] and Na2K3[SnBi3]

1998 ◽  
Vol 53 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Matthias Asbrand ◽  
Brigitte Eisenmann ◽  
Holger Engelhardt ◽  
Ute Rößler
Keyword(s):  
Crystal Structures ◽  
Covalent Bonding ◽  
Partial Structure ◽  
Alkali Cations ◽  
Orthorhombic System ◽  
Space Group ◽  
Lattice Constants ◽  
Tetrahedral Voids ◽  
Sodium And Potassium

Abstract The metallic lustrous compounds Na2K3[SnP3], Na2Cs3[SnP3], and Na2K3[SnBi3] were prepared from melts of mixtures of the elements. The isotypic compounds Na2K3[SnP3] and Na2Cs3[SnP3] crystallize in the orthorhombic system, space group Cmca (No 64), Z = 8, with lattice constants a = 1996.1 (4)/2047.9(4) pm, b = 669.5(1)/686.5(2) pm, c = 1494.5(2)/1617.8(3) pm. The structure is characterized by dimeric units [Sn2P6] 10- of edge-sharing [SnP4] tetrahe­dra, which are coordinated by the alkali cations. Na2K3[SnBi3] crystallizes in the orthorhombic system, space group Ibca (No 73), Z = 8, with lattice constants a = 718.2(1) pm , b -1692.6(2) pm, c = 2159.5(2) pm. In the anionic partial structure [SnBi4] tetrahedra are connected via common corners to infinite 1∞[SnBi3]5- Zweier single chains. The sodium and potassium cat­ ions separate the chains from each other. Neglecting the distortions caused by covalent bonding and different radii both structure types can be classified as superstructure defect variants of the Li3Bi structure. Different orderings in the occupation of the tetrahedral voids lead to the variants in the anionic assemblies.

Syntheses and Crystal Structures of the Bromide-derivatized Lanthanoid(III) Ortho-Oxomolybdates(VI) LnBr[MoO4] (Ln = Pr, Nd, Sm, Gd– Lu)

2013 ◽  
Vol 68 (5-6) ◽  
pp. 616-624 ◽  
Author(s):  
Tanja Schustereit ◽  
Harald Henning ◽  
Thomas Schleid ◽  
Ingo Hartenbach
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Coordination Number ◽  
Coordination Sphere ◽  
Space Group ◽  
Structural Arrangement ◽  
Common Structure ◽  
Coordination Spheres ◽  
The Common ◽  
Oxygen Atoms

The lanthanoid(III) bromide ortho-oxomolybdates(VI) LnBr[MoO4] (Ln = Pr, Nd, Sm, Gd - Lu) crystallize triclinically in the space group P1 (a=686 - 689, b=713 - 741, c=1066 - 1121 pm, a =103 - 106, b =107 - 108, g = 92 - 95°) with Z =4. The crystal structure contains two crystallographically distinguishable Ln3+ cations, each one with a coordination number of seven plus one. (Ln1)3+ is surrounded by three bromide and four plus one oxide anions, while for (Ln2)3+ just one bromide and six plus one oxide anions belong to the coordination sphere. Considering the smallest lanthanoids, however, the distances to the farthest anions increase so much that their contribution to the coordination spheres becomes negligible in both cases. The polyhedra around (Ln1)3+ are connected to each other via common edges, which consist of two crystallographically identical Br- anions (Br1). Furthermore, the common structure of the LnBr[MoO4] series contains two crystallographically different, discrete [MoO4]2- ortho-oxomolybdate(VI) tetrahedra. Two plus one oxygen atoms of each [(Mo1)O4]2- unit are used to interconnect the polyhedra around (Ln1)3+ and (Ln2)3+ together with one Br- anion (Br2). The connection between two polyhedra around (Ln2)3+ is generated exclusively by two plus one oxygen atoms of two [(Mo2)O4]2- anions. The complete structural arrangement can be considered as a bundle of primitively packed 1¥{LnBr[MoO4]} chains with two alternating motifs of linkage, which are running parallel along [012].

scholarly journals Benchmarking Coordination Number Prediction Algorithms on Inorganic Crystal Structures

2021 ◽  
Vol 60 (3) ◽  
pp. 1590-1603
Author(s):  
Hillary Pan ◽  
Alex M. Ganose ◽  
Matthew Horton ◽  
Muratahan Aykol ◽  
Kristin A. Persson ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Prediction Algorithms ◽  
Inorganic Crystal

Neutron and X-ray Diffraction Study on the Structure of Ultraphosphate Glasses

1997 ◽  
Vol 52 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Uwe Hoppe ◽  
Günter Walter ◽  
Dörte Stachel ◽  
Andrea Barz ◽  
Alex C. Hannon
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Real Space ◽  
The Other ◽  
Oxide Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Space Resolution ◽  
Epithermal Neutrons ◽  
The Mean

Abstract The high real-space resolution of neutron diffraction experiments which is provided by use of the epithermal neutrons from spallation sources was exploited in order to differentiate the unlike P-O bonds existing in the PO4 units of phosphate glass networks. The 2 P-O distance peaks, separated by about 12 pm, which were found in the zinc and the calcium ultraphosphate glasses studied are assigned to oxygen sites on bridging (OB) and terminal (OT) positions. The mean P-O distances are nearly invariable versus the growing metal oxide content which results from an elongation of the P-OB and P-OT bonds. The bond lengths which are known from the related crystal structures and from ab initio calculations show almost the same behaviour. The discussion of further details of the crystal structures leads to the conclusion that P-OB rather than P-OT distances should show more details in case of diffraction measurements of even higher real-space resolution. The change of the Zn-O coordination number from 6 to 4 versus increasing ZnO content, which was obtained in previous X-ray diffraction experiments, is confirmed by the recent combination of neutron and X-ray diffraction data. On the other hand, the Ca-O coordination number of about 6 is almost invariable.

Au3SnCuP10 and Au3SnP7: Preparation and Crystal Structures of Au3Sn Heterocluster Polyphosphides

2006 ◽  
Vol 61 (7) ◽  
pp. 871-881 ◽  
Author(s):  
Stefan Lange ◽  
Tom Nilges
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
Homologous Series ◽  
Structure Refinement ◽  
Chair Conformation ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Tetrahedral Voids

The formation of Au3Sn heteroclusters completes the homologous series of M3Sn clusters observed for transition metal main-group polyphosphides. Au3SnCuP10 is cubic, space group F4̅3̅m (No. 216) with lattice parameter a = 10.3953(5) Å . The structure refinement yielded R1 = 0.0353 and wR2 = 0.0726 for 154 F2 values and 13 variables. Disordered Au3Sn heteroclusters occupy all octahedral, and adamantane like P10 cages one half of the tetrahedral voids of a face-centred cubic ( fcc) arrangement of copper. Ordered and orientationally disordered Au3Sn heteroclusters have been observed for Au3SnP7, embedded in a 1∞ [P7] polyphosphide unit formed by six-membered phosphorus rings in chair conformation which are linked by a P-bridge. Au3SnP7 is monoclinic, space group P21/m (No. 11) with lattice parameters of a = 6.219(2), b = 10.836(2), c = 6.318(2) Å , β = 108.65(2)°, V = 403.4(2) Å3, R1 = 0.0412 and wR2 = 0.0745, 1261 F2 values and 56 variables. Au3SnP7 with disordered Au3Sn clusters has slightly larger lattice parameters of a = 6.343(3), b = 10.955(3), c = 6.372(3) Å , β = 108.63(2)°, V = 419.6(2) Å3, R1 = 0.0324 and wR2 = 0.0691, 1131 F2 values and 58 variables.

Kristallstrukturen von zwei Modifikationen des Mo(IV)-Komplexsalzes [(Et2PS2)3Mo3S(S2)3]+(Et2PS2)- / Crystal Structures of Two Modifications of the Mo(IV) Complex Salt [(Et2PS2)3Mo3S(S2)3] + (Et2PS2)-

1982 ◽  
Vol 37 (11) ◽  
pp. 1437-1441 ◽  
Author(s):  
Beate Meyer ◽  
Hartmut Wunderlich
Keyword(s):  
Crystal Structures ◽  
Coordination Number ◽  
Local Symmetry ◽  
Complex Salt ◽  
X Ray ◽  
Anions And Cations ◽  
R Factors

Tris(diothyldithiophosphinato)-tris-μ-disulfido-μ3-thiotriangulo-trimolybdenum(IV)-di-ethyldithiophosphinate, [(et2PS2)3Mo3S(S2)3+(et2PS2)-, crystallizes in two orthorhombic modifications with crystallographic parameters of A: a = 20.651(3), b=10.152(2), c = 19.019(2) Å, Pca21, Z = 4 and B: a = 20.128(2), b= 15.655(2), c = 12.608(1) Å, Pinna, Z = 4. Both crystal structures were determined from 2886 (A) and 3414 (B) X-ray data with R factors of 0.058 and 0.045, respectively. The Mo atoms form a trinuclear Mo3S(S2)3 cluster with local symmetry close to C3V in both modifications which differ in the packing of anions and cations and in the conformation of the ethyl groups. The av. distance Mo-Mo is 2.737 Å, the coordination number of the Mo atoms is 7 within the cluster and 9 on inclusion of the S atoms of the dithiophosphinato group.

Crystal structures of potassium, ammonium, rubidium, and cesium tetrafluoborates

1969 ◽  
Vol 47 (14) ◽  
pp. 2579-2586 ◽  
Author(s):  
M. J. R. Clark ◽  
H. Lynton
Keyword(s):  
Hydrogen Bond ◽  
Standard Deviation ◽  
Crystal Structures ◽  
Orthorhombic Symmetry ◽  
Hydrogen Atoms ◽  
Anisotropic Temperature ◽  
Final Agreement ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Atomic Parameters

The crystal structures of potassium, ammonium, and rubidium tetrafluoborates have been redetermined. The structure of cesium tetrafluoborate has also been established. These 4 compounds are isomorphous and show orthorhombic symmetry, space group Pbnm. Atomic parameters have been obtained from a block diagonal least squares refinement using anisotropic temperature parameters. The final agreement residuals for observed reflections were KBF4, R = 0.072; NH4BF4, R = 0.075; RbBF4, R = 0.064; and CsBF4, R = 0.051.There are significant differences between some of the B—F bond distances in the [BF4]− ions. The shortest N—(H)F distance in NH4BF4 is 2.914 Å (estimated standard deviation 0.005 Å) which is long for a hydrogen bond. The positions of the hydrogen atoms in the NH4+ ion could not be established.

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