Electron Deformation Density Distribution in α-Boron

1987 ◽  
Vol 97 ◽  
Author(s):  
G. Will ◽  
B. Kiefer ◽  
B. Morosin ◽  
G. A. Slack
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Distribution Free ◽  
Deformation Density ◽  
Difference Density ◽  
Density Maps ◽  
Density Analysis ◽  
Electron Density Analysis

ABSTRACTThe bonding features of α-boron were studied using electron density analysis procedures. Deformation density maps and valence density were calculated and the structure analysed by so-called multipole refinements, yielding R - 0.0119. The refinement model correctly describes the bonding and results in a difference density distribution free from any meaningful residual peaks.

scholarly journals Exploring charge density analysis in crystals at high pressure: data collection, data analysis and advanced modelling

2017 ◽  
Vol 73 (4) ◽  
pp. 584-597 ◽  
Author(s):  
Nicola Casati ◽  
Alessandro Genoni ◽  
Benjamin Meyer ◽  
Anna Krawczuk ◽  
Piero Macchi
Keyword(s):  
High Pressure ◽  
Density Distribution ◽  
Charge Density ◽  
Electron Density ◽  
Electron Density Distribution ◽  
Theoretical Work ◽  
Specific Information ◽  
Collection Data ◽  
Modelling Techniques ◽  
Density Analysis

The possibility to determine electron-density distribution in crystals has been an enormous breakthrough, stimulated by a favourable combination of equipment for X-ray and neutron diffraction at low temperature, by the development of simplified, though accurate, electron-density models refined from the experimental data and by the progress in charge density analysis often in combination with theoretical work. Many years after the first successful charge density determination and analysis, scientists face new challenges, for example: (i) determination of the finer details of the electron-density distribution in the atomic cores, (ii) simultaneous refinement of electron charge and spin density or (iii) measuring crystals under perturbation. In this context, the possibility of obtaining experimental charge density at high pressure has recently been demonstrated [Casatiet al.(2016).Nat. Commun.7, 10901]. This paper reports on the necessities and pitfalls of this new challenge, focusing on the speciessyn-1,6:8,13-biscarbonyl[14]annulene. The experimental requirements, the expected data quality and data corrections are discussed in detail, including warnings about possible shortcomings. At the same time, new modelling techniques are proposed, which could enable specific information to be extracted, from the limited and less accurate observations, like the degree of localization of double bonds, which is fundamental to the scientific case under examination.

Atomic interactions in ethylenebis(1-indenyl)zirconium dichloride as derived by experimental electron density analysis

2005 ◽  
Vol 61 (4) ◽  
pp. 418-428 ◽  
Author(s):  
Adam I. Stash ◽  
Kiyoaki Tanaka ◽  
Kazunari Shiozawa ◽  
Hitoshi Makino ◽  
Vladimir G. Tsirelson
Keyword(s):  
Electron Density ◽  
Topological Analysis ◽  
Electronic Energy ◽  
Ligand Interaction ◽  
Atomic Interactions ◽  
Particle Potential ◽  
Density Analysis ◽  
The One ◽  
Electron Density Analysis ◽  
Experimental Electron Density

A topological analysis of the experimental electron density in racemic ethylenebis(1-indenyl)zirconium dichloride, C20H16Cl2Zr, measured at 100 (1) K, has been performed. The atomic charges calculated by the numerical integration of the electron density over the zero-flux atomic basins demonstrate the charge transfer of 2.25 e from the Zr atom to the two indenyl ligands (0.19 e to each) and two Cl atoms (0.93 e to each). All the atomic interactions were quantitatively characterized in terms of the electron density and the electronic energy-density features at the bond critical points. The Zr—C2 bond paths significantly curved towards the C1—C2 bond were found; no other bond paths connecting the Zr atom and indenyl ligand were located. At the same time, the π-electrons of the C1—C2 bond are significantly involved in the metal–ligand interaction. The electron density features indicate that the indenyl coordination can be approximately described as η1 with slippage towards η2. The `ligand-opposed' charge concentrations around the Zr atom were revealed using the Laplacian of the electron density and the one-particle potential; they were linked to the orbital representations. Bonds in the indenyl ligand were characterized using the Cioslowski–Mixon bond-order indices calculated directly from the experimental electron density.

Sign in / Sign up

Export Citation Format

Share Document