Results 181 to 190 of about 3,648 (206)
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Spanning Set of Silica Cluster Isomer Topologies from QTAIM
The Journal of Physical Chemistry A, 2011Structural and chemical properties of the building block of silica nanowires, (SiO(2))(6), are investigated with the theory of atoms and molecules (QTAIM). Twenty-five conformers have been analyzed, ten of which have not been reported before. We extend the silica (SiO(2))(6) topology phase space using QTAIM; the Poincaré-Hopf topological sum rules are ...
Samantha, Jenkins +4 more
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QTAIM electron density study of natural chalcones
Chemical Physics Letters, 2007Abstract QTAIM atomic and bond properties, ionization potential, and O–H bond dissociation energies calculated at the B3LYP/6-311++G(2d,2p) level indicate the natural chalcones bear a significant radical scavenging activity. However, their ionization potentials indicate they decrease the electron-transfer rate between antioxidant and oxygen that ...
María J. González Moa +3 more
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On bond-critical points in QTAIM and weak interactions
Journal of Molecular Modeling, 2018Bond critical points (BCPs) in the quantum theory of atoms in molecules (QTAIM) are shown to be a consequence of the molecular topology, symmetry, and the Poincaré-Hopf relationship, which defines the numbers of critical points of different types in a scalar field.
Christian R. Wick, Timothy Clark
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QTAIM Characteristics of Halogen Bond and Related Interactions
The Journal of Physical Chemistry A, 2012Different types of noncovalent interactions such as, for example, halogen bond, hydrogen bond, and dihalogen bond are analyzed. The analysis is based on ab initio calculations which were performed on complexes of the F(3)CCl molecule. This choice is connected with the features of the Cl atom which may act as the Lewis acid and also as the Lewis base ...
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QTAIM Analysis in the Context of Quasirelativistic Quantum Calculations
Journal of Chemical Theory and Computation, 2014Computational chemistry currently lacks ad hoc tools for probing the nature of chemical bonds in heavy and superheavy-atom systems where the consideration of spin-orbit coupling (SOC) effects is mandatory. We report an implementation of the Quantum Theory of Atoms-In-Molecules in the framework of two-component relativistic calculations.
Pilme, Julien +5 more
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QTAIM Study of an α-Helix Hydrogen Bond Network
The Journal of Physical Chemistry B, 2009The structures of 19 alpha-helical alanine-based peptides, 13 amino acids in length, have been fully optimized using density functional theory and analyzed by means of the quantum theory of atoms in molecules. Two types of N-H...O bonds and one type of C-H...O bond have been identified. The value of the electron density at hydrogen bond critical points
Shenna M, Lapointe +3 more
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On the Physical Nature of Halogen Bonds: A QTAIM Study
The Journal of Physical Chemistry A, 2013In this article, we report a detailed study on halogen bonds in complexes of CHCBr, CHCCl, CH2CHBr, FBr, FCl, and ClBr with a set of Lewis bases (NH3, OH2, SH2, OCH2, OH(-), Br(-)). To obtain insight into the physical nature of these bonds, we extensively used Bader's Quantum Theory of Atoms-in-Molecules (QTAIM).
Syzgantseva, Olga A. +2 more
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Microsolvation of aminoethanol: a study using DFT combined with QTAIM
Journal of Molecular Modeling, 2011The microsolvation of aminoethanol (AE) with one, two, three or four water molecules was investigated using a density functional theory (DFT) approach. Quantum theory of atoms in molecules (QTAIM) analyses were employed to elucidate the hydrogen-bonding characteristics of AE-(H(2)O)( n ) (n = 1-4 ...
Zhengguo, Huang +3 more
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A fast and accurate algorithm for QTAIM integration in solids
Journal of Computational Chemistry, 2010AbstractA new algorithm is presented for the calculation of atomic properties, in the sense of the quantum theory of atoms in molecules. This new method, namedQTREE, applies to solid‐state densities and allows the computation of the atomic properties of all the atoms in the crystal in seconds to minutes.
A, Otero-de-la-Roza, Víctor, Luaña
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QTAIM charge density study of natural cinnamic acids
Chemical Physics Letters, 2006Abstract B3LYP/6-311++G(2d,2p) 6d ionization potentials and O–H bond dissociation energies of natural cinnamic acids are consistent with an important antioxidant activity. The QTAIM analysis indicates that: (i) the benzene ring and the propenoic acid fragment of cinnamic acids behave as independent π systems; (ii) the ionization process consists in a
María J. González Moa +2 more
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