scholarly journals Charge-density and electrostatic properties of curcumin: an experimental study

2017 ◽  
Vol 73 (a2) ◽  
pp. C705-C705
Author(s):  
Saravanan Kandasamy
Keyword(s):  
Experimental Study ◽  
Charge Density ◽  
Electrostatic Properties

Dynamics of charge density wave phase-slips in mesoscopic samples

2002 ◽  
Vol 12 (9) ◽  
pp. 165-168
Author(s):  
S. N. Artemenko
Keyword(s):  
Experimental Study ◽  
Theoretical Model ◽  
Charge Density ◽  
Qualitative Agreement ◽  
Charge Density Wave ◽  
Temporal Evolution ◽  
Density Wave ◽  
Thermal Fluctuations ◽  
Charge Density Wave Phase ◽  
Phase Slips

Theoretical model of current conversion from normal to collective current in mesoscopic samples of CDW conductors is presented. The current conversion is described in terms of phase slips (PS) induced by strain of the CDW and stimulated by thermal fluctuations. Kernels of PS situated near contacts are surrounded by long-range perturbations of the CDW phase. If spacing between contacts is shorter than decaying length of these perturbations then temporal evolution of PS at different contacts becomes correlated, and PS voltage decreases with spacing between the contacts decreasing. The results are in qualitative agreement with experimental study of current conversion in submicron NbSe3 wires.

Topological analysis of electron density and the electrostatic properties of isoniazid: an experimental and theoretical study

2014 ◽  
Vol 70 (2) ◽  
pp. 331-341 ◽  
Author(s):  
Gnanasekaran Rajalakshmi ◽  
Venkatesha R. Hathwar ◽  
Poomani Kumaradhas
Keyword(s):  
Hydrogen Bonding ◽  
Charge Density ◽  
Electron Density ◽  
Topological Analysis ◽  
Bond Critical Point ◽  
Potential Region ◽  
Electrostatic Properties ◽  
Structural And Electronic Properties ◽  
Density Analysis ◽  
Mycobacterial Cell Wall

Isoniazid (isonicotinohydrazide) is an important first-line antitubercular drug that targets the InhA enzyme which synthesizes the critical component of the mycobacterial cell wall. An experimental charge-density analysis of isoniazid has been performed to understand its structural and electronic properties in the solid state. A high-resolution single-crystal X-ray intensity data has been collected at 90 K. An aspherical multipole refinement was carried out to explore the topological and electrostatic properties of the isoniazid molecule. The experimental results were compared with the theoretical charge-density calculations performed usingCRYSTAL09with the B3LYP/6-31G** method. A topological analysis of the electron density reveals that the Laplacian of electron density of the N—N bond is significantly less negative, which indicates that the charges at the b.c.p. (bond-critical point) of the bond are least accumulated, and so the bond is considered to be weak. As expected, a strong negative electrostatic potential region is present in the vicinity of the O1, N1 and N3 atoms, which are the reactive locations of the molecule. The C—H...N, C—H...O and N—H...N types of intermolecular hydrogen-bonding interactions stabilize the crystal structure. The topological analysis of the electron density on hydrogen bonding shows the strength of intermolecular interactions.

scholarly journals Electrostatic properties of zeolites from charge density modelling: Success after pitfalls?

2000 ◽  
Vol 56 (s1) ◽  
pp. s194-s194
Author(s):  
F. Porcher ◽  
E. Aubert ◽  
M. Souhassou ◽  
Y. Dusausoy ◽  
C. Lecomte
Keyword(s):  
Charge Density ◽  
Electrostatic Properties ◽  
Density Modelling

Experimental study of X-ray charge density and the selection of reference points for a source function in η6-(2-methyl-1,4-dihydro-2H-3,1-benzoxazine)tricarbonylchromium(0)

2019 ◽  
Vol 29 (3) ◽  
pp. 346-348 ◽  
Author(s):  
Georgy K. Fukin ◽  
Anton V. Cherkasov ◽  
Roman V. Rumyantcev ◽  
Natalia Yu. Grishina ◽  
Elena V. Sazonova ◽  
...  
Keyword(s):  
Experimental Study ◽  
Charge Density ◽  
Source Function ◽  
Reference Points ◽  
X Ray ◽  
Selection Of

Experimental and theoretical charge density, intermolecular interactions and electrostatic properties of metronidazole

2019 ◽  
Vol 75 (6) ◽  
pp. 942-953 ◽  
Author(s):  
Chinnasamy Kalaiarasi ◽  
Christy George ◽  
Rajesh G. Gonnade ◽  
Venkatesha R. Hathwar ◽  
Kumaradhas Poomani
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Intermolecular Interactions ◽  
Topological Analysis ◽  
Intramolecular Hydrogen Bonding ◽  
Bond Critical Point ◽  
Monoclinic System ◽  
Electrostatic Properties ◽  
Negative Laplacian ◽  
Intramolecular Hydrogen

Metronidazole is a radiosensitizer; it crystallizes in the monoclinic system with space group P21/c. The crystal structure of metronidazole has been determined from high-resolution X-ray diffraction measurements at 90 K with a resolution of (sin θ/λ)max = 1.12 Å−1. To understand the charge-density distribution and the electrostatic properties of metronidazole, a multipole model refinement was carried out using the Hansen–Coppens multipole formalism. The topological analysis of the electron density of metronidazole was performed using Bader's quantum theory of atoms in molecules to determine the electron density and the Laplacian of the electron density at the bond critical point of the molecule. The experimental results have been compared with the corresponding periodic theoretical calculation performed at the B3LYP/6-31G** level using CRYSTAL09. The topological analysis reveals that the N—O and C—NO2 exhibit less electron density as well as negative Laplacian of electron density. The molecular packing of crystal is stabilized by weak and strong inter- and intramolecular hydrogen bonding and H...H interactions. The topological analysis of O—H...N, C—H...O and H...H intra- and intermolecular interactions was also carried out. The electrostatic potential of metronidazole, calculated from the experiment, predicts the possible electrophilic and nucleophilic sites of the molecule; notably, the hydroxyl and the nitro groups exhibit large electronegative regions. The results have been compared with the corresponding theoretical results.

Charge density distribution and electrostatic interactions of ethionamide: an inhibitor of the enoyl acyl carrier protein reductase (inhA) enzyme of Mycobacterium tuberculosis

RSC Advances ◽  
2014 ◽  
Vol 4 (101) ◽  
pp. 57823-57833 ◽  
Author(s):  
G. Rajalakshmi ◽  
Mysore S. Pavan ◽  
P. Kumaradhas
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Density Distribution ◽  
Charge Density ◽  
Intermolecular Interactions ◽  
Electrostatic Interactions ◽  
Acyl Carrier Protein ◽  
Carrier Protein ◽  
Charge Density Distribution ◽  
Electrostatic Properties ◽  
Density Analysis

The experimental and theoretical charge density analysis of ethionamide molecule provides the topological and the electrostatic properties, which allows the understanding of the nature of intra- and intermolecular interactions.

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