Characterization of Complicated New Polymorphs of Chlorothalonil by X-ray Diffraction and Computer Crystal Structure Prediction

2004 ◽  
Vol 126 (22) ◽  
pp. 7071-7081 ◽  
Author(s):  
Maryjane Tremayne ◽  
Leanne Grice ◽  
James C. Pyatt ◽  
Colin C. Seaton ◽  
Benson M. Kariuki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Crystal Structure Prediction ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Surface Induced Phenytoin Polymorph. 1. Full Structure Solution by Combining Grazing Incidence X-ray Diffraction and Crystal Structure Prediction

2019 ◽  
Vol 19 (11) ◽  
pp. 6058-6066 ◽  
Author(s):  
Doris E. Braun ◽  
Arianna Rivalta ◽  
Andrea Giunchi ◽  
Natalia Bedoya-Martinez ◽  
Benedikt Schrode ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Grazing Incidence ◽  
Crystal Structure Prediction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Solution ◽  
Full Structure

Structural investigation ofN,N′-methylenebisacrylamideviaX-ray diffraction assisted by crystal structure prediction

2015 ◽  
Vol 48 (2) ◽  
pp. 550-557 ◽  
Author(s):  
Claudia Graiff ◽  
Daniele Pontiroli ◽  
Laura Bergamonti ◽  
Chiara Cavallari ◽  
Pier Paolo Lottici ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Prediction ◽  
Density Functional ◽  
Geometry Optimization ◽  
Lattice Energy ◽  
Strong Interactions ◽  
Crystal Structure Prediction ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure ofN,N′-methylenebisacrylamide was determined through the geometry optimization of the molecular unit with density functional theory and conformational analysis, and then through the calculation of the packingviaa crystal structure prediction protocol, based on lattice energy minimization. All the calculated structures were ranked, comparing their powder pattern with the laboratory low-quality X-ray diffraction data. Rietveld refinement of the best three proposed structures allowed the most probable crystal arrangement of the molecules to be obtained. This approach was essential for disentangling the twinning problems affecting the single-crystal X-ray diffraction data, collected on samples obtainedviarecrystallization of powder, which definitely confirmed the predicted model. It was found thatN,N′-methylenebisacrylamide shows a monoclinic structure in the space groupC2/c, with lattice parametersa= 17.822 (12),b= 4.850 (3),c= 19.783 (14) Å, β = 102.370 (9)°,V= 1670 (2) Å3. Two strong interactions between the amide protons and the carbonyl groups of neighbouring molecules were found along thebaxis, determining the crystal growth in the form of wires in this direction. This work provides a further example of how computational methods may help to investigate low-quality molecular crystals with standard diffraction techniques.

Crystal Structure of Levofloxacin Anhydrates: A High-Temperature Powder X-ray Diffraction Study Versus Crystal Structure Prediction

2018 ◽  
Vol 18 (6) ◽  
pp. 3558-3568 ◽  
Author(s):  
Jennifer T. J. Freitas ◽  
Cristiane C. de Melo ◽  
Olímpia M. M. S. Viana ◽  
Fabio F. Ferreira ◽  
Antonio C. Doriguetto
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Diffraction Study ◽  
Structure Prediction ◽  
Crystal Structure Prediction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Versus Crystal

Crystal structure determination by combined synchrotronpowder X-ray diffraction and crystal structure prediction: 1 : 1 l-ephedrined-tartrate

CrystEngComm ◽  
2013 ◽  
Vol 15 (10) ◽  
pp. 1853-1859 ◽  
Author(s):  
Han Wu ◽  
Matthew Habgood ◽  
Julia E. Parker ◽  
Nik Reeves-McLaren ◽  
Jeremy K. Cockcroft ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Structure Prediction ◽  
Crystal Structure Determination ◽  
Crystal Structure Prediction ◽  
X Ray Diffraction ◽  
X Ray

New similarity index for crystal structure determination from X-ray powder diagrams

2005 ◽  
Vol 38 (6) ◽  
pp. 861-866 ◽  
Author(s):  
Detlef Walter Maria Hofmann ◽  
Ludmila Kuleshova
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Structure Prediction ◽  
Similarity Index ◽  
Crystal Structure Determination ◽  
Crystal Structure Prediction ◽  
X Ray ◽  
Organic Pigments ◽  
Structure Solution ◽  
Similarity Indices

A new similarity index for automated comparison of powder diagrams is proposed. In contrast to traditionally used similarity indices, the proposed method is valid in cases of large deviations in the cell constants. The refinement according to this index closes the gap between crystal structure prediction and automated crystal structure determination. The opportunities of the new procedure have been demonstrated by crystal structure solution of un-indexed powder diagrams of some organic pigments (PY111, PR181 and Me-PR170).

scholarly journals Serendipitous formation and characterization of K2[Pd(NO3)4]·2HNO3

2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
Glass Ampoule ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.

Crystal structure, thermodynamic properties and detonation characterization of bis(5-amino-1,2,4-triazol-3-yl)methane

2020 ◽  
Vol 76 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hongya Li ◽  
Biao Yan ◽  
Haixia Ma ◽  
Zhiyong Sun ◽  
Yajun Ma ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Detonation Velocity ◽  
Theoretical Calculations ◽  
Detonation Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equivalent Equation ◽  
Experimental Values ◽  
Experimental Density

Bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM, C5H8N8) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group Fdd2 (orthorhombic) with Z = 8. The structure of BATZM can be described as a V-shaped molecule with reasonable chemical geometry and no disorder. The specific molar heat capacity (Cp,m ) of BATZM was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 211.19 J K−1 mol−1 at 298.15 K. The relative deviations between the theoretical and experimental values of Cp,m , HT – H 298.15K and ST – S 298.15K of BATZM are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM were estimated using the nitrogen equivalent equation according to the experimental density; BATZM has a higher detonation velocity (7954.87 ± 3.29 m s−1) and detonation pressure (25.72 ± 0.03 GPa) than TNT.

Structural and magnetic characterization of Ho3SbO7 and Dy3SbO7

2001 ◽  
Vol 79 (11-12) ◽  
pp. 1415-1419 ◽  
Author(s):  
T Fennell ◽  
S T Bramwell ◽  
M A Green
Keyword(s):  
Crystal Structure ◽  
Experimental Investigation ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Magnetic Characterization ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Ice Model ◽  
Magnetic Rare Earth

We present an experimental investigation of the structural and magnetic properties of Ho3SbO7 and Dy3SbO7. These compounds adopt the Y3TaO7 structure, space group C2221. The magnetic rare-earth ions occupy an intricate lattice related to the pyrochlore lattice that occurs in Ho2Ti2O7 and Dy2Ti2O7. The crystal structure of Ho3SbO7 is determined by Rietveld refinement of the powder X-ray diffraction pattern at ambient temperature, and that of the Dy analogue is inferred to be similar. Magnetic susceptibility measurements show that Ho3SbO7 and Dy3SbO7 have negative Curie–Weiss temperatures: –8.4 K (Ho) and –9.2 K (Dy). Magnetic transitions have been detected at 2.0 K (Ho) and 3.0 K (Dy). We discuss the results in terms of the ``dipolar spin ice model'' that has been used to describe Ho2Ti2O7 and Dy2Ti2O7. PACS Nos.: 75.25+z, 75.50Ee, 61.10Nz

Structural and IR-spectroscopic characterization of magnesium acesulfamate

2016 ◽  
Vol 71 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Elemental Analysis ◽  
Spectroscopic Characterization ◽  
Magnesium Carbonate ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Ir Spectroscopic

AbstractMagnesium acesulfamate, Mg(C4H4NO4S)2·6H2O, was prepared by the reaction of acesulfamic acid and magnesium carbonate in aqueous solution, and characterized by elemental analysis. Its crystal structure was determined by single crystal X-ray diffraction methods. The substance crystallizes in the triclinic space group P1̅ with one molecule per unit cell. The FTIR spectrum of the compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate and saccharinate salts are also made.

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