Basic crystallographic data of anhydrous hexaamidocyclotriphosphazene and its monohydrate

1981 ◽  
Vol 46 (7) ◽  
pp. 1625-1628
Author(s):  
Milan Kouřil ◽  
Zdirad Žák
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Least Squares Method ◽  
Lattice Parameters ◽  
Crystallographic Data ◽  
Crystal Data ◽  
Space Groups

Powder photographs of (PN(NH2)2)3 and (PN(NH2)2)3.H2O were indexed based on the lattice parameters obtained from the single crystal data, and the parameters were refined by using the least-squares method. The space groups belonging to the two crystalline substances are Pcba (Z = 8) and P1 (P1) (Z = 2), respectively.

X-ray powder diffraction analysis of adducts triglycine fluoroberyllic acid and triglycine selenic acid for pyroelectric application

2001 ◽  
Vol 16 (3) ◽  
pp. 167-169 ◽  
Author(s):  
Yunxia Che ◽  
Jimin Zheng ◽  
Jianmin Hao ◽  
Lianqing Chu
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Least Squares ◽  
Powder Diffraction ◽  
Structure Data ◽  
Crystal Structure Data ◽  
Least Squares Method ◽  
Lattice Parameters ◽  
X Ray

Two adducts (NH2CH2COOH)3⋅H2BeF4(TGFb) and (NH2CH2COOH)3⋅H2SeO4(TGSe) were obtained and characterized by X-ray powder diffraction. The samples were indexed using the TREOR program [Werner, Z. Kristallogr. Kristallogeom. Kristallphys. Kristallchem. 120, 375–387 (1964)] on a monoclinic unit cell. The lattice parameters of adducts TGFb and TGSe were refined by a least-squares method using the Lattice Constant Refinement Program of the Rikagu software. The refined lattice parameters are a=9.1589(9) Å, b=12.6204(13) Å, c=5.6966(8) Å, β=105.451(9)° for TGFb. The Smith and Snyder figure [Smith and Snyder, J. Appl. Crystallogr. 12, 60–65 (1979)] is F30=39.4(0.0141,54). The refined lattice parameters a=9.5063(11) Å, b=12.8281(10) Å, c=5.8682(7) Å, β=110.353(77)° for TGSe. The Smith and Snyder figure is F30=39(0.0106,73). The powder diffraction results are in agreement with those obtained from single crystal structure data.

Notizen: Synthesis and Crystal Data of the Bismuth Sulphide Chloride B19Si27Cl3

1974 ◽  
Vol 29 (9-10) ◽  
pp. 688-689 ◽  
Author(s):  
Volker Krämer
Keyword(s):  
Title Compound ◽  
Hexagonal Lattice ◽  
Lattice Parameters ◽  
Crystal Data ◽  
X Ray ◽  
Space Groups ◽  
Sinter Technique

The title compound was synthesized by a sinter technique at 560°C. X ray powder data are listed, the hexagonal lattice parameters are a = 15.403 (3) and c = 4.015 (2) Å; possible space groups are P63 and P63/m.

A least-squares method for the determination of the orientation matrix in single-crystal diffractometry

1970 ◽  
Vol 26 (2) ◽  
pp. 295-296 ◽  
Author(s):  
K. Tichý
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Least Squares Method ◽  
Reciprocal Vector ◽  
Orientation Matrix ◽  
The Matrix

An appropriate choice of the function minimized permits linearization of the least-squares determination of the matrix which transforms the diffraction indices into the components of the reciprocal vector in the diffractometer φ-axis system of coordinates. The coefficients of the least-squares equations are based on diffraction indices and measured diffractometer angles of three or more non-coplanar setting reflexions.

Crystal structure of 'calcium sulphosilicate', Ca5(SiO4)2SO4

1974 ◽  
Vol 27 (3) ◽  
pp. 657 ◽  
Author(s):  
PD Brotherton ◽  
JM Epstein ◽  
MW Pryce ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Lattice Parameters ◽  
Crystal Data ◽  
Full Matrix ◽  
Lime Kiln

The crystal structure of the title compound, obtained as a coating from a lime kiln, has been shown to be isostructural with that of the mineral silicocarnotite and refined by full-matrix least-squares methods (570 independent diffractometer reflections). The lattice parameters of the latter compound were used to initiate the procedure, the final residual being 0.042. The correspondence in detail between the two structures is close. Crystal data: orthorhombic, Pcmn, a = 10.182(1), b = l5.398(2), c = 6.8500(9) �, Z = 4.

Crystal Structure of ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

Zur Darstellung und Kristallstruktur von AgCrO2 / Synthesis and Crystal Structure of AgCrO2

1975 ◽  
Vol 30 (9-10) ◽  
pp. 659-661 ◽  
Author(s):  
Egbert Gehle ◽  
Horst Sabrowsky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
Crystal Data ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Point Position ◽  
Elemental Silver ◽  
Thallium Oxide

A novel preparation is reported for AgCrO2 from elemental silver and Cr2O3 in the presence of thallium oxide. A refinement of the structure was undertaken by the use of diffractometric single-crystal data. The newly determined lattice parameters of the compounds (Delafossite-type), which crystallizes in the space group R 3 m, are : α = 2.985 Å, c = 18.51 Å; c/a = 6.20; number of formula units Z = 3 (dexp = 6.63; drö = 6.69 gcm-3). For the oxygen particles in the point position 6c z (O) = 0.1119.

Handling cell-parameter errors in crystallographic data

2009 ◽  
Vol 42 (5) ◽  
pp. 798-809 ◽  
Author(s):  
James Haestier
Keyword(s):  
Single Crystal ◽  
Cell Parameter ◽  
Covariance Matrices ◽  
Crystallographic Data ◽  
New Method ◽  
Single Crystal Diffraction ◽  
Space Groups ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters ◽  
Atomic Coordinates

A new method is presented for handling errors on crystallographic data. In single-crystal diffraction experiments, two variance–covariance matrices are present, one for the cell parameters and the second for the refined parameters (atomic coordinates and anisotropic displacement parameters). These two matrices can be combined so that errors on derived parameters, such as bond distances, bond angles and TLS tensors, may be calculated more simply. The new method works for all space groups but there are limitations on its application to triclinic space groups. The method allows errors to be transformed between space groups.

Crystal structure of Hydroxyimino(N,N'-dimethyl)malonamide

1977 ◽  
Vol 30 (9) ◽  
pp. 1929 ◽  
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Direct Methods ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound, namely hydroxyimino(N,N?- dimethyl)malonamide (MeNHCOC(=NOH)CONHMe), has been determined by single-crystal X-ray diffraction with diffractometer data at 295 K. The structure was solved by direct methods and refined by least squares to a residual of 0.055 for 1477 observed reflections. ��� Crystal data: monoclinic, P21/n, a 15.508(3), b 10.544(2), c 9.377(1) Ǻ, β 103.15(2)�, Z 8. ��� The two crystallographically independent molecules exhibit little conjugation throughout the C-C-C skeleton (<C-C> 1.50 Ǻ), the molecule being non-planar. <C=O> is 1.234, <N-CH3> 1.443, <OC-N> 1.323, <C-NO> 1.278 and (N-O) 1.375 Ǻ. The geometry is compared with those observed for several related derivatives.

Powder diffraction analysis of substituted sulfonylurea

2002 ◽  
Vol 17 (1) ◽  
pp. 48-51 ◽  
Author(s):  
Yu PuLan ◽  
Ding Shuang ◽  
Qiao YuanYuan ◽  
Yao XinKan ◽  
Zhang HaiYue ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Least Squares ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Data ◽  
Cell Parameters ◽  
Cell Dimensions ◽  
Good Agreement

The crystal structure of a series of substituted sulfonylureas were studied in this paper by means of powder diffraction, and the cell dimensions of each compound were refined by a least squares analysis. The cell parameters were in good agreement with those obtained from single crystal data. © 2002 International Centre for Diffraction Data.

The synthesis, X-ray structure, and substitution lability of chloro(2,3,7,8,12,13,17,18-octaethylporphinato)(triphenylphosphine)rhodium(III)

1986 ◽  
Vol 64 (12) ◽  
pp. 2440-2446 ◽  
Author(s):  
David C. Thackray ◽  
Sara Ariel ◽  
Tak W. Leung ◽  
Kusum Menon ◽  
Brian R. James ◽  
...  
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Thermodynamic Data ◽  
Crystal Data ◽  
X Ray ◽  
Thermal Reactions ◽  
Photochemical Processes ◽  
Rhodium Atom ◽  
Ring Nitrogen ◽  
The Mean

The rhodium(III) octaethylporphyrin complex Rh(OEP)(PPh3)Cl (1) has been synthesized via Rh(III) or Rh(I) precursors, and fully characterized both by spectroscopy and single crystal data. The crystals, available as a bis(chloroform) solvate are triclinic, P1, a = 13.478(5), b = 14.300(5), c = 15.346(4) Å, α = 102.33(2), β = 102.89(2), γ = 90.56(3)°, Z = 2, Dx = 1.384 g cm−3. The structure was determined from Mo diffractometer data and refined by least-squares methods to R = 0.095, Rw = 0.068 for 5189 reflections. The octahedrally coordinated rhodium atom is displaced by 0.077 Å from the mean plane of the four N atoms, towards the triphenylphosphine group. The average Rh – ring nitrogen distance is 2.024 Å, Rh—P is 2.306(3) Å and Rh—Cl, 2.442(2) Å. Solution equilibria studies on 1 describe formation of Rh(OEP)L2+ (L = PPh3, PnBu3) via thermal reactions (including thermodynamic data for the PPh3 system), and formation of Rh(OEP)Cl(L′) species (L′ = CO, THF, MeCN) via photochemical processes.

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