scholarly journals Topological analysis of chemical bonding in the layered FePSe 3 upon pressure‐induced phase transitions

2020 ◽  
Vol 41 (31) ◽  
pp. 2610-2623
Author(s):  
Robert A. Evarestov ◽  
Alexei Kuzmin
Keyword(s):  
Phase Transitions ◽  
Chemical Bonding ◽  
Topological Analysis

scholarly journals Topology of the Electron Density and of Its Laplacian from Periodic LCAO Calculations on f-Electron Materials: The Case of Cesium Uranyl Chloride

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4227
Author(s):  
Alessandro Cossard ◽  
Silvia Casassa ◽  
Carlo Gatti ◽  
Jacques K. Desmarais ◽  
Alessandro Erba
Keyword(s):  
Electron Density ◽  
Chemical Bonding ◽  
Topological Analysis ◽  
Theoretical Description ◽  
Basis Functions ◽  
Quantum Mechanical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Orbitals ◽  
Uranyl Chloride

The chemistry of f-electrons in lanthanide and actinide materials is yet to be fully rationalized. Quantum-mechanical simulations can provide useful complementary insight to that obtained from experiments. The quantum theory of atoms in molecules and crystals (QTAIMAC), through thorough topological analysis of the electron density (often complemented by that of its Laplacian) constitutes a general and robust theoretical framework to analyze chemical bonding features from a computed wave function. Here, we present the extension of the Topond module (previously limited to work in terms of s-, p- and d-type basis functions only) of the Crystal program to f- and g-type basis functions within the linear combination of atomic orbitals (LCAO) approach. This allows for an effective QTAIMAC analysis of chemical bonding of lanthanide and actinide materials. The new implemented algorithms are applied to the analysis of the spatial distribution of the electron density and its Laplacian of the cesium uranyl chloride, Cs2UO2Cl4, crystal. Discrepancies between the present theoretical description of chemical bonding and that obtained from a previously reconstructed electron density by experimental X-ray diffraction are illustrated and discussed.

The quantitative analysis of electrostatic potential and study of chemical bonding by electron diffraction structure analysis

2003 ◽  
Vol 218 (4) ◽  
Author(s):  
A. S. Avilov
Keyword(s):  
Quantitative Analysis ◽  
Electron Diffraction ◽  
Structure Analysis ◽  
Electrostatic Potential ◽  
Chemical Bonding ◽  
Quantitative Data ◽  
Topological Analysis ◽  
Diffraction Structure ◽  
Academy Of Sciences ◽  
Electron Diffractometry

AbstractThe development of the electron diffractometry methods jointly the analytical methods of electrostatic potential (ESP) reconstruction and its topological analysis allowd one to proceed to the quality new level of electron diffraction structure analysis (EDSA): investigation inner crystalline electrostatic field, which knowledge permitts to study the relation of the atomic structure with physical properties of crystals. The review of the last achivements in this direction, obtained in the Institute of Crystallography of Russian Academy of Sciences, in which EDSA method was discovered, is done. The possibility of the EDSA method to solve precise problems of quantitative analysis of the electrostatic potential is shown on the examples of investigations of the ESP distributions and chemical bonding in crystals with NaCl-type structure and covalent crystal Ge. It is also shown that quantitative data on the potential distribution considerably enlarge conceptions on the nature of interatomic and inetrmolecular interactions in crystals.

Is there a future for topological analysis in experimental charge-density research?

2017 ◽  
Vol 73 (3) ◽  
pp. 325-329 ◽  
Author(s):  
Birger Dittrich
Keyword(s):  
Charge Density ◽  
Intermolecular Interaction ◽  
Intermolecular Interactions ◽  
Chemical Bonding ◽  
Topological Analysis ◽  
Theoretical Chemistry ◽  
Research Tool ◽  
Interaction Energies ◽  
Research Focus ◽  
Experimental Charge Density

Topological analysis using Bader and co-worker'sAtoms in Moleculestheory has seen many applications in theoretical chemistry and experimental charge-density research. A brief overview of successful early developments, establishing topological analysis as a research tool for characterizing intramolecular chemical bonding, is provided. A lack of vision in many `descriptive but not predictive' subsequent studies is discussed. Limitations of topology for providing accurate energetic estimates of intermolecular interaction energies are put into perspective. It is recommended that topological analyses of well understood bonding situations are phased out and are only reported for unusual bonding. Descriptive studies of intermolecular interactions should have a clear research focus.

ZrCuSiAs-type Phosphide Oxides: TbRuPO, DyRuPO, the Series LnOsPO (Ln = La, Ce, Pr, Nd, Sm), and ThAgPO

2008 ◽  
Vol 63 (8) ◽  
pp. 934-940 ◽  
Author(s):  
Wolfgang Jeitschko ◽  
Barbara I. Zimmer ◽  
Robert Glaum ◽  
Ludger Boonk ◽  
Ute Ch. Rodewald
Keyword(s):  
Phase Transitions ◽  
Solid State ◽  
Single Crystal ◽  
Chemical Bonding ◽  
Large Family ◽  
Type Structure ◽  
Solid State Reactions ◽  
X Ray ◽  
History Of ◽  
High Transition

The title compounds were prepared by solid-state reactions and via tin and NaCl/KCl fluxes. They crystallize with the tetragonal ZrCuSiAs-type structure (P4/nmm, Z = 2), which was refined from single-crystal X-ray data of PrOsPO (a = 402.1(1), c = 824.0(1) pm, wR2 = 0.0490, 365 F2) and ThAgPO (a = 396.1(1), c = 877.8(1) pm, wR2 = 0.0307, 314 F2). They belong to a large family of isotypic compounds, of which several, mainly fluorine doped, iron containing compounds LnFeAsO1-xFx were discovered to be superconducting with relatively high transition temperatures only recently in other laboratories. Chemical bonding in these compounds is briefly discussed, and the importance of the weakly bonding Fe-Fe interactions for the phase transitions and the superconductivity is emphasized from the viewpoint of structural chemistry. A brief account of the history of the preparation of these compounds in our laboratory is given. Originally many of these compounds were obtained only in small amounts as byproducts in the course of the preparation of ternaries.

Chemical bonding in pentaerythritol at very low temperature or at high pressure: an experimental and theoretical study

2006 ◽  
Vol 62 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Elizabeth A. Zhurova ◽  
Vladimir G. Tsirelson ◽  
Vladimir V. Zhurov ◽  
Adam I. Stash ◽  
A. Alan Pinkerton
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Low Temperature ◽  
Intermolecular Interaction ◽  
Electron Density ◽  
Chemical Bonding ◽  
Topological Analysis ◽  
Interaction Energies ◽  
Molecular Layers ◽  
Very Low Temperature

Chemical bonding in the pentaerythritol crystal based on the experimental electron density at 15 (1) K, and theoretical calculations at the experimental molecular geometries obtained at room and low (15 K) temperatures have been analyzed and compared in terms of the topological analysis. Topological electron-density features corresponding to the high-pressure (1.15 GPa) geometry are also reported. In addition to the bond critical points (CPs) within the molecular layers, CPs between the atoms of different molecular layers have been located and the bonding character of these relatively weak interactions discussed. Atomic charges and energies have been integrated over the atomic basins delimited by the zero-flux surfaces, and the intermolecular interaction energies have been calculated. The interaction between molecular layers in the crystal becomes stronger both at very low temperature and high pressure, as demonstrated by the more negative intermolecular interaction energies, higher electron density and energy density values at the CPs, and sharper electronic-energy density profiles.

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