Electrostatic potential in dehydrated zeolite NaA from low-resolution x-ray diffraction data

1988 ◽  
Vol 92 (3) ◽  
pp. 794-796 ◽  
Author(s):  
Mark A. Spackman ◽  
Hans Peter Weber
Keyword(s):  
Electrostatic Potential ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Low Resolution ◽  
X Ray ◽  
Zeolite Naa

scholarly journals Application of maximum-entropy electrostatic potential in Materials Science.

2014 ◽  
Vol 70 (a1) ◽  
pp. C101-C101
Author(s):  
Eiji Nishibori
Keyword(s):  
Maximum Entropy ◽  
Electrostatic Potential ◽  
Diffraction Data ◽  
Materials Science ◽  
Structural Information ◽  
Entropy Method ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Sites

Charge density (CD) studies by Maximum Entropy Method (MEM) (Sakata & Sato, 1990) from x-ray diffraction data have been widely applied to solve problems and questions in materials science during past two decades. Encapsulations of metal atoms (Takata et al, 1995), gas molecules, as well as protein molecules in the materials have been visualized as MEM CDs. The MEM CD technique is now regarded as a sophisticated technique for visualization in atomic scale. Electrostatic potential (EP) and electric field (EF) from x-ray diffraction data using MEM have been developed in 2006 (Tanaka et al, 2006). The EP & EF successfully applied to ferroelectric material PbTiO3 and a charge ordered manganite system. The method has huge potential in materials science since interaction in the non-atomic region can be visualized experimentally. One of the promising target for EP & EF analysis is host-guest systems, such as porous coordination polymers (PCPs), zeolites, clathrates as well as endohedral metallofullerenes[3]. In the case of host-guest systems, the guest atom(s) or molecule(s) are located in spatially wider sites in comparison to other type of materials. Therefore the detailed structural information in the spatially wider sites is one of the most important issues. In the present study, I present an application of MEM EP & EF analysis to host-guest related system, icosahedral B12 cluster materials and hydrogen adsorbed PCP. The EP studies clearly visualize doping sites in B12 based superconductor and adsorption sites in PCP. The EF enables us to estimate quantitative interaction from host to guest. The quantitative evaluation really bridges between experiment and theory in materials science.

Electrostatic Properties of Ions in Crystals from X-Ray Diffraction Data

1993 ◽  
Vol 48 (1-2) ◽  
pp. 81-84 ◽  
Author(s):  
Niels K. Hansen
Keyword(s):  
Density Distribution ◽  
Charge Density ◽  
Electrostatic Potential ◽  
Diffraction Data ◽  
Reciprocal Space ◽  
Electrostatic Energy ◽  
X Ray Diffraction ◽  
Charge Density Distribution ◽  
X Ray ◽  
Space Approach

Abstract A procedure for calculating the electrostatic potential and the electrostatic energy of an ion in a crystal is presented. It is based on a mixed direct and reciprocal space approach, and it takes into account the detailed charge density distribution in the crystal which can be obtained from accurate X-ray diffraction measurements.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Crystallization and preliminary x-ray diffraction data of the cryptomonad biliprotein phycocyanin-645 from a Chroomonas spec.

1984 ◽  
Vol 140 (2-3) ◽  
pp. 202-205 ◽  
Author(s):  
Walter Morisset ◽  
Werner Wehrmeyer ◽  
Tilman Schirmer ◽  
Wolfram Bode
Keyword(s):  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

Theoretically derived thermodynamic properties can be improved by the refinement of low-frequency modes against X-ray diffraction data

2021 ◽  
Author(s):  
Anna Agnieszka Hoser ◽  
Marcin Sztylko ◽  
Damian Trzybiński ◽  
Anders Østergaard Madsen
Keyword(s):  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Diffraction Data ◽  
Molecular Crystals ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Efficient Approach

A framework for estimation of thermodynamic properties for molecular crystals via refinement of frequencies from DFT calculations against X-ray diffraction data is presented. The framework provides an efficient approach to...

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

The modulated structure of Bi2Sr3−xCaxCu2O8: A commensurate model from single crystal X-ray diffraction data

1989 ◽  
Vol 161 (5-6) ◽  
pp. 598-606 ◽  
Author(s):  
G. Calestani ◽  
C. Rizzoli ◽  
M.G. Francesconi ◽  
G.D. Andreetti
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray

scholarly journals Crystallographic features of ammonium fluoroelpasolites: dynamic orientational disorder in crystals of (NH4)3HfF7 and (NH4)3Ti(O2)F5

2017 ◽  
Vol 73 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Anatoly A. Udovenko ◽  
Alexander A. Karabtsov ◽  
Natalia M. Laptash
Keyword(s):  
Single Crystal ◽  
Electron Density ◽  
Diffraction Data ◽  
Central Atom ◽  
X Ray Diffraction ◽  
Dynamic Nature ◽  
Orientational Disorder ◽  
High Quality ◽  
Structural Units ◽  
X Ray

A classical elpasolite-type structure is considered with respect to dynamically disordered ammonium fluoro-(oxofluoro-)metallates. Single-crystal X-ray diffraction data from high quality (NH4)3HfF7 and (NH4)3Ti(O2)F5 samples enabled the refinement of the ligand and cationic positions in the cubic Fm \bar 3 m (Z = 4) structure. Electron-density atomic profiles show that the ligand atoms are distributed in a mixed (split) position instead of 24e. One of the ammonium groups is disordered near 8c so that its central atom (N1) forms a tetrahedron with vertexes in 32f. However, a center of another group (N2) remains in the 4b site, whereas its H atoms (H2) occupy the 96k positions instead of 24e and, together with the H3 atom in the 32f position, they form eight spatial orientations of the ammonium group. It is a common feature of all ammonium fluoroelpasolites with orientational disorder of structural units of a dynamic nature.

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