The crystal structure of buttgenbachite

1973 ◽  
Vol 39 (303) ◽  
pp. 264-270 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi ◽  
A. R. Zanzari
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Least Squares ◽  
Three Dimensional ◽  
Intensity Data ◽  
Cell Content ◽  
Space Group ◽  
Patterson Function

SummaryThe crystal structure of buttgenbachite from Likasi (Congo) was solved by a three- dimensional Patterson function, computed using intensity data collected photographically by the Weissenberg method, and refined by successive Fourier maps and least-squares refinement to an R index 0·055 for 328 independent observed reflections. The cell content resulting from the structural analysis is Cu36·6Cl6·7(NO3)2·6(OH)63·9.2·1 H2O. The space group is P63/mmc with a = 15·750 Å and c = 9·161Å. The buttgenbachite structure is not completely ordered. It consists of a rigid three-dimensional skeleton formed by Cu co-ordination polyhedra sharing edges and corners. The large channels in the framework show a zeolite-like nature; inside the channels the disorder is caused by the different orientations of nitrate groups and by the occurrence of the substitution . The crystal structure of buttgenbachite is closely related to that of connellite. The mechanism of forming an isomorphous series is discussed: the present study shows that the replacement is more complicated than was supposed in the literature.

The crystal structure of dundasite

1972 ◽  
Vol 38 (297) ◽  
pp. 564-569 ◽  
Author(s):  
G. Cocco ◽  
L Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Three Dimensional ◽  
Water Molecules ◽  
Intensity Data ◽  
Chemical Formula ◽  
Orthorhombic Space Group ◽  
Coordination Polyhedra ◽  
Patterson Function ◽  
Pb Ions

SummaryThe crystal structure of dundasite from Gonnesa (Italy) was solved by a three-dimensional Patterson function computed using intensity data collected photographically by the Weissenberg method, and refined by successive Fourier maps and least-squares cycles to an R index 0·.066 for 505 independent observed reflections.The chemical formula resulting from the structural analysis is PbAl2(CO3)2(OH)4·H2O. The mineral is orthorhombic, space group Pbnm, with a 9·08 Å, b 16·37 Å, c 5·62 Å. The dundasite structure consists of a three-dimensional framework of coordination polyhedra around Pb and Al. Pb ions are coordinated by nine oxygen atoms with distances ranging from 2·53 to 2·91 Å. Al ions show the usual octahedral coordination with average Al-O distance 1.90 Å. C-O mean distances are 1·28 and 1·27 Å for the two non-equivalent CO3 groups. The water molecules are not coordinated by the cations.

Protoenstatite: a crystal-structure refinement at 1100°C

1971 ◽  
Vol 134 (3-4) ◽  
Author(s):  
Joseph R. Smyth
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Single Crystal ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Intensity Data ◽  
Crystal Structure Refinement ◽  
Space Group

AbstractTechniques allowing single-crystal investigations on the precession camera up to the melting point of platinum have been developed. The crystal structure of protoenstatite has been refined from three-dimensional intensity data obtained at 1100°C using a crystal of enstatite from the Norton County, Kansas meteorite. The space group is

The crystal structure of kogarkoite, Na3SO4F

1980 ◽  
Vol 43 (330) ◽  
pp. 753-759 ◽  
Author(s):  
L. Fanfani ◽  
G. Giuseppetti ◽  
C. Tadini ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Thermal Parameters ◽  
Cell Content ◽  
Space Group ◽  
X Ray ◽  
Structural Relationships ◽  
Automatic Diffractometer ◽  
Monoclinic Cell

SummaryThe crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

The crystal structure of ferrinatrite, Na3(H2O)3[Fe(SO4)3] and its relationship to Maus's salt, (H3O)2K2{K0.5(H2O)0.5}6[Fe3O(H2O)3(SO46](OH)2

1977 ◽  
Vol 41 (319) ◽  
pp. 375-383 ◽  
Author(s):  
F. Scordari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Three Dimensional ◽  
Iron Ions ◽  
Space Group ◽  
R Value ◽  
Oxygen Atoms

SummaryFerrinatrite crystallizes in space group P, with a = 15·566(5), c = 8·69(1) Å, and Z = 6. The crystal structure was solved by three-dimensional Patterson and Fourier syntheses, and refined by least squares employing 2378 independent reflexions to a final R value of 0·068. The iron ions occupy special positions and are surrounded octahedrally by oxygen atoms. Fe3+O6 octahedra and SO4, tetrahedra are linked together to form infinite chains of Fe-O-S linkages in the [0001] direction. These chains are linked to each other by [NaO5(H2O)2] polyhedra and probably by hydrogen bonds. The topology of the arrangement is the same as that of the hypothetical P312 structure proposed by Moore and Araki (1974).

The crystal structure of manganese (II) L-tartrate tetrahydrate MnC4H4O6 · 4H2O

1985 ◽  
Vol 171 (3-4) ◽  
Author(s):  
H. Soylu
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Three Dimensional ◽  
Orthorhombic Space Group ◽  
Space Group

AbstractThe crystal structure of manganese (II) L-tartrate tetrahydrate has been determined and refined by three-dimensional least-squares methods. The crystals are orthorhombic, space group

Verfeinerung der Kristallstruktur eines basaltischen Magnesio-Hastingsites

1981 ◽  
Vol 156 (3-4) ◽  
Author(s):  
E. M. Walitzi ◽  
F. Walter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the basaltic clino-amphibole magnesio-hastingsite was refined from three-dimensional photographic X-ray data by a full matrix least-squares method in the space group

THE CRYSTAL STRUCTURE OF K2TeBr6

1964 ◽  
Vol 42 (12) ◽  
pp. 2758-2767 ◽  
Author(s):  
I. D. Brown
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Least Squares ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cubic Form ◽  
Efficient Packing

Crystals of K2TeBr6 are monoclinic, space group [Formula: see text] with a = 7.521, b = 7.574, and c = 10.730 Å; β = 89° 40′. Atomic positions have been found by three dimensional X-ray diffraction analysis (least squares R = 0.12). The crystals possess a K2PtCl6 structure which is distorted to allow a more efficient packing of the comparatively large anions than is possible with the undistorted cubic form. The stereochemistry of the octahedral TeBr6− ion (Te—Br = 2.71 Å) is discussed.

The crystal and molecular structure of aqua-bis(ethylenediamine)cupric-tris(cyano)-selenocyanatodicuprate

1982 ◽  
Vol 47 (10) ◽  
pp. 2623-2632 ◽  
Author(s):  
Viktor Vrábel ◽  
Jan Lokaj ◽  
Ján Garaj ◽  
František Pavelčík
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structural Analysis ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Triclinic System

The crystal structure of [Cu(H2O)(en)2][Cu2(CN)3(SeCN)] was solved by single crystal X-ray structural analysis in the triclinic system with a space group of P1 and in the monoclinic system with a space group of C2. In the triclinic system the unit cell has dimensions of a = 0.8445(3), b = 0.7903(3), c = 0.8444(3) nm, α = 119.58(2), β = 118.59(2) and γ = 93.63(3)° and, in the monoclinic system, a = 1.3331(4), b = 0.8670(2), c = 0.8267(3), β = 122.60(2)°. The structure was refined by the least squares method to final value of R = 5.5% in the triclinic system and R = 7.8% in the monoclinic system. The coordination sphere around the Cu(II) atom is square pyramidal, formed of two ethylenediamine molecules and one water molecule. The Cu(I) atoms are tetrahedrally coordinated by bridging SeCN and CN ligands to form infinite three-dimensional chains. The SeCN group is bonded to the Cu(I) atoms through the Se atom at distances of 0.2731(3) and 0.2745(3) nm.

The crystal structure of galeite, Na15(SO4)5F4Cl

1975 ◽  
Vol 40 (312) ◽  
pp. 357-361 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi ◽  
A. R. Zanzari
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Thermal Parameters ◽  
X Ray Diffraction ◽  
Cell Content ◽  
X Ray ◽  
Structure Factors

SummaryThe crystal structure of galeite from Searles Lake (California) has been determined by means of X-ray diffraction data on a single crystal. A possible structure was derived from that of schairerite on the basis of chemical and lattice analogies and was confirmed by comparison of the observed diffractometric structure factors with the calculated ones. The refinement was performed by least-squares methods employing isotropic thermal parameters and assuming that atoms related by translational pseudosymmetry exhibit equal thermal parameters. The final R value is 0·09. The cell content is 3[Na15(SO4)5F4Cl]; the space group is P31m The lattice dimensions are a 12·197(4)Å, c 13·955(10) Å The marked subcell has P3m1 symmetry and a 7·042Å, c 13·955 Å. The crystal structure of galeite consists of a three-dimensional framework, formed by coordination octahedra around Na+ ions, including tetrahedral holes with sulphur atoms at the centres. The three-dimensional framework can be considered built up by five octahedral sheets (seven sheets can be recognized in schairerite and six in sulphohalite). The very close analogies occurring in the structures of galeite and schairerite are discussed.

Coordination compounds of Hg22+: The crystal structure of Bis(acridine)dimercury(I) perchlorate

1976 ◽  
Vol 29 (4) ◽  
pp. 723 ◽  
Author(s):  
D Taylor
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Coordination Compounds ◽  
Three Dimensional ◽  
Mercury Atom ◽  
Steric Interaction ◽  
Space Group ◽  
X Ray ◽  
Metal Ligand ◽  
Block Diagonal

Crystals of bis(acridine)dimercury(1) perchlorate, [Hg2(C13H9N)2] (ClO4)2 are monoclinic, a = 10.629(1), b = 16.841(2), c = 7.142(1) �, β = 99.06(2)�, space group I2/m with Z = 2 dimeric formula units. The structure was solved from three-dimensional diffractometer X-ray data(1427 independent reflections), block-diagonal least-squares refinement of all atoms, including hydrogens, converging at R = 0.028. The mercury dimer, Hg-Hg 295177(5)�, is coordinated in the axial positions by the acridine molecules, Hg-N 2.150(5) �, the cation having C2h symmetry.There are also two long contacts from each mercury atom to oxygen atoms of the perchlorate ions, Hg-0 2.958(6) �. Evidence for a metal-ligand steric interaction is presented.

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