Intramolecular mode coupling of the isotopomers of water: a non-scalar charge density-derived perspective

2020 ◽  
Vol 22 (4) ◽  
pp. 2509-2520
Author(s):  
Tian Tian ◽  
Tianlv Xu ◽  
Steven R. Kirk ◽  
Ian Tay Rongde ◽  
Yong Boon Tan ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Mode Coupling ◽  
Bond Critical Point ◽  
Scalar Charge

Left: The BCP trajectories T(s) for H2O for the bending (Q1) mode, the axes labels of the trajectory T(s). The green spheres correspond to the bond critical point (BCPs). Right: The corresponding T(s) for H2O for the symmetric-stretch (Q2) mode.

Benzenoid hydrocarbon aromaticity in terms of charge density descriptors

1997 ◽  
Vol 75 (9) ◽  
pp. 1174-1181 ◽  
Author(s):  
S.T. Howard ◽  
T.M. Krygowski
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Critical Points ◽  
Electron Distribution ◽  
Stationary Points ◽  
Bond Critical Point ◽  
Total Density ◽  
Benzenoid Hydrocarbon ◽  
Hartree Fock ◽  
Point Data

Hartree–Fock/6-31G** calculations on the benzenoid hydrocarbons benzene, naphthalene, phenanthrene, anthracene, pyrene, tetracene, triphenylene, chrysene, perylene, and coronene are used to investigate the link between aromaticity and the electron distribution. Topological charge density analysis is used, concentrating on the electron distribution ρ (and its Hessian) at bond and ring critical points. With regard to the bond critical point data, it is shown that ρc, [Formula: see text]ρc, and the bond "ellipticity" ε are closely correlated with the bond lengths so, as aromaticity indicators, they have little to add over and above existing indices based on structure. However, the same properties evaluated at the ring critical points in the total density, and also at the equivalent stationary points in the π and σ densities, correlate closely with two different aromaticity indices (one based on structure, the other on magnetic properties), the curvature of ρ perpendicular to the ring plane giving (marginally) the best results. Hence a ring critical point (RCP) index is proposed as a way of quantifying aromaticity, based directly on the electron distribution. Keywords: quantum chemistry, electron density, aromaticity, aromaticity index, HOMA, NICS.

scholarly journals Tuning the charge density wave quantum critical point and the appearance of superconductivity in TiSe2

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Sangyun Lee ◽  
Tae Beom Park ◽  
Jihyun Kim ◽  
Soon-Gil Jung ◽  
Won Kyung Seong ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals Multiband nodeless superconductivity near the charge-density-wave quantum critical point in ZrTe 3− x Se x

2016 ◽  
Vol 25 (7) ◽  
pp. 077403
Author(s):  
Shan Cui ◽  
Lan-Po He ◽  
Xiao-Chen Hong ◽  
Xiang-De Zhu ◽  
Cedomir Petrovic ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical

Electronegativity and Bader's bond critical point

1992 ◽  
Vol 13 (7) ◽  
pp. 912-918 ◽  
Author(s):  
Sanchita Hati ◽  
Dipankar Datta
Keyword(s):  
Critical Point ◽  
Bond Critical Point

The charge-density-wave quantum-critical-point scenario

1997 ◽  
Vol 282-287 ◽  
pp. 260-263 ◽  
Author(s):  
C. Castellani ◽  
C. Di Castro ◽  
M. Grilli
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals Coincident onset of charge-density-wave order at a quantum critical point in underdoped YBa2Cu3Ox

2018 ◽  
Vol 97 (22) ◽  
Author(s):  
H. Jang ◽  
W.-S. Lee ◽  
S. Song ◽  
H. Nojiri ◽  
S. Matsuzawa ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Point ◽  
Charge Density Wave ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals A method to estimate statistical errors of properties derived from charge-density modelling

2018 ◽  
Vol 74 (3) ◽  
pp. 170-183 ◽  
Author(s):  
Bertrand Fournier ◽  
Benoît Guillot ◽  
Claude Lecomte ◽  
Eduardo C. Escudero-Adán ◽  
Christian Jelsch
Keyword(s):  
Charge Density ◽  
Least Squares ◽  
Critical Point ◽  
Critical Points ◽  
Property Values ◽  
Density Model ◽  
Interaction Energies ◽  
Topological Properties ◽  
A Charge ◽  
Density Modelling

Estimating uncertainties of property values derived from a charge-density model is not straightforward. A methodology, based on calculation of sample standard deviations (SSD) of properties using randomly deviating charge-density models, is proposed with theMoProsoftware. The parameter shifts applied in the deviating models are generated in order to respect the variance–covariance matrix issued from the least-squares refinement. This `SSD methodology' procedure can be applied to estimate uncertainties ofanyproperty related to a charge-density model obtained by least-squares fitting. This includes topological properties such as critical point coordinates, electron density, Laplacian and ellipticity at critical points and charges integrated over atomic basins. Errors on electrostatic potentials and interaction energies are also available now through this procedure. The method is exemplified with the charge density of compound (E)-5-phenylpent-1-enylboronic acid, refined at 0.45 Å resolution. The procedure is implemented in the freely availableMoProprogram dedicated to charge-density refinement and modelling.

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.

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