scholarly journals Electron Density Geometry and the Quantum Theory of Atoms in Molecules

2021 ◽  
Author(s):  
Timothy R. Wilson ◽  
Anastassia N. Alexandrova ◽  
M. E. Eberhart
Keyword(s):  
Quantum Theory ◽  
Electron Density ◽  
Atoms In Molecules

On the transferability of electron density in binary vanadium borides VB, V3B4 and VB2

2015 ◽  
Vol 71 (6) ◽  
pp. 777-787 ◽  
Author(s):  
Bürgehan Terlan ◽  
Lev Akselrud ◽  
Alexey I. Baranov ◽  
Horst Borrmann ◽  
Yuri Grin
Keyword(s):  
Quantum Theory ◽  
Crystal Structures ◽  
Electron Density ◽  
Critical Points ◽  
Atoms In Molecules ◽  
Model Systems ◽  
Suitable Model ◽  
Interatomic Distances ◽  
Systematic Analysis ◽  
A Charge

Binary vanadium borides are suitable model systems for a systematic analysis of the transferability concept in intermetallic compounds due to chemical intergrowth in their crystal structures. In order to underline this structural relationship, topological properties of the electron density in VB, V3B4 and VB2 reconstructed from high-resolution single-crystal X-ray diffraction data as well as derived from quantum chemical calculations, are analysed in terms of Bader's Quantum Theory of Atoms in Molecules [Bader (1990). Atoms in Molecules: A Quantum Theory, 1st ed. Oxford: Clarendon Press]. The compounds VB, V3B4 and VB2 are characterized by a charge transfer from the metal to boron together with two predominant atomic interactions, the shared covalent B—B interactions and the polar covalent B—M interactions. The resembling features of the crystal structures are well reflected by the respective B—B interatomic distances as well as by ρ(r) values at the B—B bond critical points. The latter decrease with an increase in the corresponding interatomic distances. The B—B bonds show transferable electron density properties at bond critical points depending on the respective bond distances.

Experimental observation of charge-shift bond in fluorite CaF2

2017 ◽  
Vol 73 (4) ◽  
pp. 643-653 ◽  
Author(s):  
Marcin Stachowicz ◽  
Maura Malinska ◽  
Jan Parafiniuk ◽  
Krzysztof Woźniak
Keyword(s):  
Quantum Theory ◽  
Density Distribution ◽  
Critical Point ◽  
Electron Density ◽  
Closed Shell ◽  
Atoms In Molecules ◽  
Bond Critical Point ◽  
Ionic Radii ◽  
Bond Path ◽  
Charge Shift

On the basis of a multipole refinement of single-crystal X-ray diffraction data collected using an Ag source at 90 K to a resolution of 1.63 Å−1, a quantitative experimental charge density distribution has been obtained for fluorite (CaF2). The atoms-in-molecules integrated experimental charges for Ca2+and F−ions are +1.40 e and −0.70 e, respectively. The derived electron-density distribution, maximum electron-density paths, interaction lines and bond critical points along Ca2+...F−and F−...F−contacts revealed the character of these interactions. The Ca2+...F−interaction is clearly a closed shell and ionic in character. However, the F−...F−interaction has properties associated with the recently recognized type of interaction referred to as `charge-shift' bonding. This conclusion is supported by the topology of the electron localization function and analysis of the quantum theory of atoms in molecules and crystals topological parameters. The Ca2+...F−bonded radii – measured as distances from the centre of the ion to the critical point – are 1.21 Å for the Ca2+cation and 1.15 Å for the F−anion. These values are in a good agreement with the corresponding Shannon ionic radii. The F−...F−bond path and bond critical point is also found in the CaF2crystal structure. According to the quantum theory of atoms in molecules and crystals, this interaction is attractive in character. This is additionally supported by the topology of non-covalent interactions based on the reduced density gradient.

scholarly journals PolaBer: a program to calculate and visualize distributed atomic polarizabilities based on electron density partitioning

2014 ◽  
Vol 47 (4) ◽  
pp. 1452-1458 ◽  
Author(s):  
Anna Krawczuk ◽  
Daniel Pérez ◽  
Piero Macchi
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Dipole Moment ◽  
Quantum Theory ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Atomic Charge ◽  
Atoms In Molecules ◽  
Molecular Dipole ◽  
Atomic Polarizability

This paper describes the program PolaBer, which calculates atomic polarizability tensors from electric field perturbations of a partitioned electron density distribution. Among many possible partitioning schemes, PolaBer is currently using the quantum theory of atoms in molecules and it is interfaced to programs that apply such a partitioning. The calculation of the atomic tensors follows the idea suggested by Keith [The Quantum Theory of Atoms in Molecules: From Solid State to DNA and Drug Design, (2007), edited by C. F. Matta & R. J. Boyd. Weinheim: Wiley-VCH], which enables the removal of the intrinsic origin dependence of the atomic charge contributions to the molecular dipole moment. This scheme allows the export, within chemically equivalent functional groups, of properties calculated from atomic dipoles, such as for example the atomic polarizabilities. The software permits visualization of the tensors and calculation of straightforward optical properties of a molecule (like the molar refractive index) or a crystal (assuming the molecule in a given crystal lattice).

scholarly journals SULFUR-CONTAINING HETEROCYCLES OF BENZENE AND HEXANE IN THE QUANTUM THEORY OF ATOMS IN MOLECULES

2020 ◽  
pp. 53-61
Author(s):  
Наталья Петровна Русакова ◽  
Георгий Александрович Курочкин ◽  
Юлия Ивановна Софронова ◽  
Владимир Владимирович Туровцев
Keyword(s):  
Quantum Theory ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Cyclic Compound ◽  
Atoms In Molecules ◽  
Electronic Density ◽  
Donor And Acceptor ◽  
Cyclic Compounds ◽  
Sulfur Containing

Изучено распределение электронной плотности 14 циклических соединений и одного нециклического. Проведен анализ зарядов и объемов групп, найдены группы доноры и акцепторы электронной плотности. Рассмотрено изменение электронной плотности серосодержащих групп под влиянием окружения. The electron density distribution of 14 cyclic compounds and one non-cyclic compound was studied. The group charges and group volumes were analyzed, and the electron density donor and acceptor groups were found. Changes in the electronic density of sulfur-containing groups under the influence of the environment are considered.

scholarly journals ELECTRON DENSITY DISTRIBUTION IN 15-CROWN-5 AND ITS THIOANALOGS

2021 ◽  
pp. 94-103
Author(s):  
Александр Витальевич Зиганшин ◽  
Наталья Петровна Русакова ◽  
Владимир Владимирович Туровцев ◽  
Юрий Димитриевич Орлов
Keyword(s):  
Quantum Theory ◽  
Density Distribution ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Weak Interactions ◽  
Cell Structure ◽  
Atoms In Molecules ◽  
B3lyp Method ◽  
Sulfur Containing

Методом B3LYP получено распределение электронной плотности ρ(r) 15-краун-5 и его серосодержащих аналогов: 1-тио-15-краун-5, 1,4-дитио-15-краун-5, 1,4,7-тритио-15-краун-5, 1,4,7,10-тетратио-15-краун-5, 1,4,7,10,13-пентатио-15-краун-5. Вычислены групповые интегральные характеристики распределения ρ(r) соединений в рамках «квантовой теории атомов в молекулах» QTAIM. Рассмотрены внутримолекулярные слабые взаимодействия в 1,4-дитио-15-краун-5, 1,4,7-тритио-15-краун-5, 1,4,7,10-тетратио-15-краун-5, 1,4,7,10,13-пентатио-15-краун-5 и отмечено образование клеточной структуры в 1,4,7-тритио-15-краун-5. Electron density distribution of 15-crown-5 and its sulfur-containing analogs: 1-thio-15-crown-5, 1,4-dithio-15-crown-5, 1,4,7-threetio-15-crown-5, 1,4,7,10-tetratio-15-crown-5, 1,4,7,10,13-pentatio-15-crown-5 by the B3LYP method was obtained. The charges, volumes and electronic energies of the compounds are calculated in the postulates of the «quantum theory of atoms in molecules» (QTAIM). Intramolecular weak interactions are found in the 1,4-dithio-15-crown-5, 1,4,7-threetio-15-crown-5, 1,4,7,10-tetratio-15-crown-5, 1,4,7,10,13-pentatio-15-crown-5. The cell structure is formed in 1,4,7-threetio-15-crown-5.

Sign in / Sign up

Export Citation Format

Share Document