Density functional theory calculations of pentabromidooxomolybdate(V) anion with 2,2′-bipyridinium cation: Comparison between the calculated geometry and the crystal structure determination at 293 and 90K

Polyhedron ◽  
2010 ◽  
Vol 29 (3) ◽  
pp. 1109-1115 ◽  
Author(s):  
Salim F. Haddad ◽  
Basem F. Ali ◽  
Rawhi H. Al-Far ◽  
Jamal N. Dawoud ◽  
Mohammed I. Alomari
2017 ◽  
Vol 32 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Joel W. Reid ◽  
James A. Kaduk ◽  
Jeremy A. Olson

The crystal structure of Na(NH4)Mo3O10·H2O has been solved by parallel tempering using the FOX software package with synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded orthorhombic lattice parameters of a = 13.549 82(10), b = 7.618 50(6), and c = 9.302 74(7) Å (Z = 4, space group Pnma). The structure is composed of molybdate chains running parallel to the b-axis. The Rietveld refinement results were compared with density functional theory calculations performed with CRYSTAL14, and show excellent agreement with the calculated structure.


Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 464 ◽  
Author(s):  
Hebboul ◽  
Galez ◽  
Benbertal ◽  
Beauquis ◽  
Mugnier ◽  
...  

Synthesis and characterization of anhydrous LiZn(IO3)3 powders prepared from an aqueous solution are reported. Morphological and compositional analyses were carried out by using scanning electron microscopy and energy-dispersive X-ray measurements. The synthesized powders exhibited a needle-like morphology after annealing at 400 °C. A crystal structure for the synthesized compound was proposed from powder X-ray diffraction and density-functional theory calculations. Rietveld refinements led to a monoclinic structure, which can be described with space group P21, number 4, and unit-cell parameters a = 21.874(9) Å, b = 5.171(2) Å, c = 5.433(2) Å, and  = 120.93(4)°. Density-functional theory calculations supported the same crystal structure. Infrared spectra were also collected, and the vibrations associated with the different modes were discussed. The non-centrosymmetric space group determined for this new polymorph of LiZn(IO3)3, the characteristics of its infrared absorption spectrum, and the observed second-harmonic generation suggest it is a promising infrared non-linear optical material.


2016 ◽  
Vol 72 (6) ◽  
pp. 660-666 ◽  
Author(s):  
Ahmet Gulec ◽  
Xiaoxiang Yu ◽  
Matthew Taylor ◽  
John H. Perepezko ◽  
Laurence Marks

Z-contrast imaging, electron diffraction, atom-probe tomography (APT) and density functional theory calculations were used to study the crystal structure of the Mo3Si phase which was previously reported to have an A15 crystal structure. The results showed that Mo3Si has an incommensurate crystal structure with a non-cubic unit cell. The small off-stoichiometry in composition of the sample which was revealed by APT and atomic resolutionZ-contrast imaging suggested that site substitution caused the development of split atomic positions, disorder and vacancies.


2017 ◽  
Vol 72 (11) ◽  
pp. 839-846
Author(s):  
Sebastian Plebst ◽  
Martina Bubrin ◽  
David Schweinfurth ◽  
Stanislav Záliš ◽  
Wolfgang Kaim

AbstractThe compounds [W(CO)5(btd)], [W(CO)5(bsd] and [Re(CO)3(bpy)(bsd)](BF4), btd=2,1,3-benzothiadiazole and bsd=2,1,3-benzoselenadiazole were isolated and characterized experimentally (crystal structure, spectroscopy, spectroelectrochemistry) and by density functional theory calculations. The results confirm single N-coordination in all cases, binding to Se was calculated to be less favorable. Studies of one-electron reduced forms indicate that the N-coordination is maintained during electron transfer.


2014 ◽  
Vol 118 (18) ◽  
pp. 9652-9658 ◽  
Author(s):  
Javier Sánchez-Benítez ◽  
Paula Kayser ◽  
Ángel Morales-García ◽  
María Jesús Martínez-Lope ◽  
Federico J. Mompeán ◽  
...  

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