ChemInform Abstract: Crystal Structure and Charge Density Analysis of Ca(BH4)2.

ChemInform ◽  
2010 ◽  
Vol 41 (13) ◽  
Author(s):  
T. Noritake ◽  
M. Aoki ◽  
M. Matsumoto ◽  
K. Miwa ◽  
S. Towata ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
Density Analysis

Approaches to crystal structure landscape exploration

2017 ◽  
Vol 73 (5) ◽  
pp. 775-778 ◽  
Author(s):  
Gautam R. Desiraju
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
Structure Prediction ◽  
Crystal Structure Prediction ◽  
Density Analysis

Three approaches to the exploration of the crystal structure landscape are outlined. These are crystal structure prediction, non-ambient crystallography and charge density analysis.

Least-Squares Methods and Their Use in Charge Density Analysis

1997 ◽  
Author(s):  
Philip Coppens
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
Least Squares ◽  
Structure Refinement ◽  
Error Function ◽  
Crystal Structure Refinement ◽  
Fourier Techniques ◽  
Density Analysis ◽  
Least Squares Techniques

The number of reflection intensities measured in a crystallographic experiment is large, and commonly exceeds the number of parameters to be determined. It was first realized by Hughes (1941) that such an overdetermination is ideally suited for the application of the least-squares methods of Gauss (see, e.g., Whittaker and Robinson 1967), in which an error function S, defined as the sum of the squares of discrepancies between observation and calculation, is minimized by adjustment of the parameters of the observational equations. As least-squares methods are computationally convenient, they have largely replaced Fourier techniques in crystal structure refinement. In addition to the positional and thermal parameters of the atoms, least-squares procedures are used to determine the scale of the data, and parameters such as mosaic spread or particle size, which influence the intensities through multiple-beam effects (Becker and Coppens 1974a, b, 1975). It is not an exaggeration to say that modern crystallography is, to a large extent, made possible by the use of least-squares methods. Similarly, least-squares techniques play a central role in the charge density analysis with the scattering formalisms described in the previous chapter. The following description follows closely the treatment given by Hamilton (1964).

Crystal structure and charge density analysis of Li2NH by synchrotron X-ray diffraction

2005 ◽  
Vol 393 (1-2) ◽  
pp. 264-268 ◽  
Author(s):  
T. Noritake ◽  
H. Nozaki ◽  
M. Aoki ◽  
S. Towata ◽  
G. Kitahara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Analysis

Crystal structure, quantum chemical and theoretical charge density analysis of 5‑bromo-2-(4-methylbenzyl)-6-(4-nitrophenyl)imidazo[2,1-b][1,3,4] thiadiazole

2020 ◽  
Vol 25 ◽  
pp. 100326
Author(s):  
A. Sowmya ◽  
G.N. Anil Kumar ◽  
Sujeet Kumar ◽  
Subhas S. Karki
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
Quantum Chemical ◽  
Density Analysis

Crystal Structure and Charge Density Analysis of Li2NH by Synchrotron X-Ray Diffraction.

ChemInform ◽  
2005 ◽  
Vol 36 (29) ◽  
Author(s):  
T. Noritake ◽  
H. Nozaki ◽  
M. Aoki ◽  
S. Towata ◽  
G. Kitahara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Analysis

Experimental and theoretical charge-density analysis of hippuric acid: insight into its binding with human serum albumin

2019 ◽  
Vol 75 (4) ◽  
pp. 750-762 ◽  
Author(s):  
Asma Hasil ◽  
Arshad Mehmood ◽  
Maqsood Ahmed
Keyword(s):  
Crystal Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Charge Density ◽  
Human Serum ◽  
Hippuric Acid ◽  
Noncovalent Interactions ◽  
Dipole Moments ◽  
Topological Analysis ◽  
Density Analysis

In order to comprehend the binding of an important metabolite, hippuric acid, with human serum albumin and to understand its chemical and electronic nature, an experimental charge-density analysis has been carried out using high-resolution diffraction data collected under cryogenic conditions, and all the results have been compared with theoretical findings using the B3LYP/6-311++g(2d,2p) level of theory. The structure displays very strong classical hydrogen bonds as well as other noncovalent interactions, which have been fully characterized using Hirshfeld surface analysis and Bader's quantum theory of atoms in molecules. Contact analysis on the Hirshfeld surfaces shows that the O...H, C...H and C...N intermolecular interactions are enriched and gives their relative strengths. Topological analysis of the electron density shows the charge concentration/depletion of hippuric acid bonds in the crystal structure. Electrostatic parameters such as atomic charges and dipole moments were calculated. The mapping of atomic basins and the calculation of respective charges show the atomic volumes of each atom as well as their charge contributions in the hippuric acid crystal structure. The dipole-moment calculations show that the molecule is very polar in nature. Calculations of the electrostatic potential show that the chain part of the molecule has a higher concentration of negative charge than the ring, which might be instrumental in its strong binding with the polar residues of site II of human serum albumin.

scholarly journals Ultra-high Resolution Crystal Structure and Charge Density Analysis of High-potential Iron-sulfur Protein, HiPIP

2016 ◽  
Vol 58 (6) ◽  
pp. 267-272
Author(s):  
Kazuki TAKEDA ◽  
Kunio MIKI ◽  
Yu HIRANO
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Charge Density ◽  
High Potential ◽  
Iron Sulfur ◽  
Density Analysis ◽  
Sulfur Protein ◽  
Iron Sulfur Protein

Crystal structure and charge density analysis of Ca(BH4)2

2010 ◽  
Vol 491 (1-2) ◽  
pp. 57-62 ◽  
Author(s):  
T. Noritake ◽  
M. Aoki ◽  
M. Matsumoto ◽  
K. Miwa ◽  
S. Towata ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Charge Density ◽  
Density Analysis

Revisiting the charge density analysis of 2,5-dichloro-1,4-benzoquinone at 20 K

2017 ◽  
Vol 73 (4) ◽  
pp. 654-659 ◽  
Author(s):  
Zhijie Chua ◽  
Bartosz Zarychta ◽  
Christopher G. Gianopoulos ◽  
Vladimir V. Zhurov ◽  
A. Alan Pinkerton
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Topological Analysis ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Total Electron Density ◽  
Total Electron ◽  
Structure Factors ◽  
Density Analysis ◽  
Experimental Charge Density

A high-resolution X-ray diffraction measurement of 2,5-dichloro-1,4-benzoquinone (DCBQ) at 20 K was carried out. The experimental charge density was modeled using the Hansen–Coppens multipolar expansion and the topology of the electron density was analyzed in terms of the quantum theory of atoms in molecules (QTAIM). Two different multipole models, predominantly differentiated by the treatment of the chlorine atom, were obtained. The experimental results have been compared to theoretical results in the form of a multipolar refinement against theoretical structure factors and through direct topological analysis of the electron density obtained from the optimized periodic wavefunction. The similarity of the properties of the total electron density in all cases demonstrates the robustness of the Hansen–Coppens formalism. All intra- and intermolecular interactions have been characterized.

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