Hydrogen bonding system in euchroite, Cu2(AsO4)(OH)(H2O)3: low-temperature crystal-structure refinement and solid-state density functional theory modeling

2016 ◽  
Vol 110 (6) ◽  
pp. 877-883 ◽  
Author(s):  
Sergey V. Krivovichev ◽  
Andrey A. Zolotarev ◽  
Igor V. Pekov
2010 ◽  
Vol 65 (10) ◽  
pp. 1235-1239 ◽  
Author(s):  
Ludwig Stork ◽  
Paul Müller ◽  
Manfred Speldrich ◽  
Paul Kögerler ◽  
Jörg von Appen ◽  
...  

The manganese-rich ternary cementite phase Mn1.8Fe1.2C has been synthesized by a ceramic route in an almost quantitative yield, and the crystal structure refinement on the basis of high-resolution X-ray powder diffraction data using MoKα1 radiation has been performed. The carbon atom is found in a slightly distorted trigonal prism composed of Mn and Fe atoms, with a rather narrow bond length range from 1.95 to 2.09 Å . The magnetic susceptibility data clearly indicate long-range ordering phenomena, in particular dominant antiferromagnetic interactions, as predicted by density-functional theory.


2021 ◽  
pp. 1-8
Author(s):  
Joel W. Reid ◽  
James A. Kaduk

The crystal structure of donepezil hydrochloride, form III, has been solved with FOX using laboratory powder diffraction data previously submitted to and published in the Powder Diffraction File. Rietveld refinement with GSAS yielded monoclinic lattice parameters of a = 14.3662(9) Å, b = 11.8384(6) Å, c = 13.5572(7) Å, and β = 107.7560(26)° (C24H30ClNO3, Z = 4, space group P21/c). The Rietveld-refined structure was compared to a density functional theory (DFT)-optimized structure, and the structures exhibit excellent agreement. Layers of donepezil molecules parallel to the (101) planes are maintained by columns of chloride anions along the b-axis, where each chloride anion hydrogen bonds to three donepezil molecules each.


Polyhedron ◽  
2013 ◽  
Vol 50 (1) ◽  
pp. 602-611 ◽  
Author(s):  
Manashi Chakraborty ◽  
Sathi Roychowdhury ◽  
Nikhil Ranjan Pramanik ◽  
Tapas Kumar Raychaudhuri ◽  
Tapan Kumar Mondal ◽  
...  

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.


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.


Sign in / Sign up

Export Citation Format

Share Document