Results 151 to 160 of about 5,247 (193)

On bond-critical points in QTAIM and weak interactions

Journal of Molecular Modeling, 2018
Bond 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, Clark Timothy   +2 more
exaly   +3 more sources

Should environmental effects be included when performing QTAIM calculations on actinide systems? A comparison of QTAIM metrics for Cs2UO2Cl4, U(Se2PPh2)4 and Np(Se2PPh2)4 in gas phase, COSMO and PEECM [PDF]

Polyhedron, 2016
Quantum Theory of Atoms-in-Molecules bond critical point and delocalisation index metrics are calculated for the actinide-element bonds in Cs2UO2Cl4, U(Se2PPh2)4 and Np(Se2PPh2)4, in gas-phase, continuum solvent (COSMO) and via the periodic electrostatic
Andrew Kerridge, Nikolas Kaltsoyannis
exaly   +2 more sources

Ultra-fast laser pulses as a probe of electron dynamics: A next generation QTAIM perspective [PDF]

Chemical Physics Letters
We investigate the construction of an ultra-fast laser probe to determine the response of the electron dynamics of ethane using next generation QTAIM (NG-QTAIM). This is undertaken by applying a pair of simulated left and right circularly polarized ultra-
Xiaoxi Xu, Herbert Früchtl, Tanja van Mourik   +2 more
exaly   +2 more sources

AIM-UC: An application for QTAIM analysis

Journal of Computational Methods in Sciences and Engineering, 2014
In this paper we introduce AIM-UC, a free application that allows to create graphs related to Quantum Theory of Atoms in Molecules (QTAIM). The input data are files that contain 3D grid of electron density, in some known formats: CUBE from gaussian, grd from DMol and CHGCAR from VASP. Also it supports wave function files from AIMPAC.
David Vega, D. Almeida
openaire   +1 more source

QTAIM study of the protonation of indole

Chemical Physics Letters, 2006
Abstract QTAIM atomic and bond properties as well as delocalization indices computed on B3LYP/6-311++(2d, 2p) and MP2/6-31++G(d, p) electron densities are employed to explain the protonation preference of indole for C3 site. In spite of displaying a very small increase of its total electron population, N1 is significantly stabilized in the preferred ...
Nicolás Otero, María J. González Moa, Marcos Mandado, Ricardo A. Mosquera   +3 more
openaire   +1 more source

Intramolecular Hydrogen Bonds: the QTAIM and ELF Characteristics

The Journal of Physical Chemistry A, 2011
B3LYP/aug-cc-pVTZ calculations were performed on the species with intramolecular O-H···O hydrogen bonds. The Quantum Theory of Atoms in Molecules (QTAIM) and the Electron Localization Function (ELF) method were applied to analyze these interactions. Numerous relationships between ELF and QTAIM parameters were found. It is interesting that the CVB index
Franck, Fuster, Sławomir J, Grabowski
openaire   +2 more sources

QTAIM Analysis in the Context of Quasirelativistic Quantum Calculations

Journal of Chemical Theory and Computation, 2014
Computational 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, Eric, Renault, Bassal, Fadel, Amaouch, Mohamed, Montavon, Gilles, Galland, Nicolas   +5 more
openaire   +4 more sources

A fast and accurate algorithm for QTAIM integration in solids

Journal of Computational Chemistry, 2010
AbstractA 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.
Alberto Otero-de-la-Roza, Víctor Luaña
openaire   +2 more sources

Characteristics of beryllium bonds; a QTAIM study

Journal of Molecular Modeling, 2012
The nature of beryllium bonds formed between BeX2 (X is H, F and Cl) and some Lewis bases have been investigated. The distribution of the Laplacian of electron density shows that there is a region of charge depletion around the Be atom, which, according to Laplacian complementary principal, can interact with a region of charge concentration of an atom ...
openaire   +2 more sources

Effects from Basis Sets and Levels of Calculations on the Nature of Interactions Predicted by QTAIM Dual Functional Analysis with QTAIM Functions

ChemistrySelect, 2019
Abstract Investigations concerning the nature of interactions must be considered an issue of primary importance in the chemical sciences. The dynamic and static natures of interactions were recently proposed based on the quantum theory of atoms in molecules dual functional analysis (QTAIM‐DFA).
Satoko Hayashi, Taro Nishide, Waro Nakanishi   +2 more
exaly   +2 more sources