Difference between revisions of "Electron-density distribution"
KevinYager (talk | contribs) |
KevinYager (talk | contribs) |
||
| Line 1: | Line 1: | ||
The '''electron-density distribution''' is the three-dimensional [[realspace]] arrangement of the electrons in the material. Because electrons are [[quantum mechanics|quantum mechanically]] [[wave packet|delocalized]], each electron occupies a 'fuzzy' region of space. The total electron density--the summation of the electron distribution for every electron in every atom--is thus inherently spread spatially; e.g a map of electron distribution will have diffuse boundaries. Nevertheless, when the electron distribution is visualized, it is often shown as a surface, representing an isosurface of constant electron-density. | The '''electron-density distribution''' is the three-dimensional [[realspace]] arrangement of the electrons in the material. Because electrons are [[quantum mechanics|quantum mechanically]] [[wave packet|delocalized]], each electron occupies a 'fuzzy' region of space. The total electron density--the summation of the electron distribution for every electron in every atom--is thus inherently spread spatially; e.g a map of electron distribution will have diffuse boundaries. Nevertheless, when the electron distribution is visualized, it is often shown as a surface, representing an isosurface of constant electron-density. | ||
| − | The exact electron-density distribution within a [[unit cell]] of a crystal can be reconstructed by carefully fitting the peak heights measured in an [[x-ray]] [[diffraction]] experiment ('structure solution'). | + | The exact electron-density distribution within a [[unit cell]] of a crystal can be reconstructed by carefully fitting the peak heights measured in an [[x-ray]] [[diffraction]] experiment ([[crystallography|crystallographic]] 'structure solution'). |
The electron distribution at a larger scale can be similarly reconstructed by fitting small-angle [[scattering]] data ([[SAXS]] or [[GISAXS]]). In this case, one is probing the average electron-density distribution at the nanoscale, without resolving the exact arrangement of electron-distribution (atoms) within this nanostructure. | The electron distribution at a larger scale can be similarly reconstructed by fitting small-angle [[scattering]] data ([[SAXS]] or [[GISAXS]]). In this case, one is probing the average electron-density distribution at the nanoscale, without resolving the exact arrangement of electron-distribution (atoms) within this nanostructure. | ||
Revision as of 14:05, 16 December 2014
The electron-density distribution is the three-dimensional realspace arrangement of the electrons in the material. Because electrons are quantum mechanically delocalized, each electron occupies a 'fuzzy' region of space. The total electron density--the summation of the electron distribution for every electron in every atom--is thus inherently spread spatially; e.g a map of electron distribution will have diffuse boundaries. Nevertheless, when the electron distribution is visualized, it is often shown as a surface, representing an isosurface of constant electron-density.
The exact electron-density distribution within a unit cell of a crystal can be reconstructed by carefully fitting the peak heights measured in an x-ray diffraction experiment (crystallographic 'structure solution').
The electron distribution at a larger scale can be similarly reconstructed by fitting small-angle scattering data (SAXS or GISAXS). In this case, one is probing the average electron-density distribution at the nanoscale, without resolving the exact arrangement of electron-distribution (atoms) within this nanostructure.
References
- Mads R. V. Jørgensen, Venkatesha R. Hathwar, Niels Bindzus, Nanna Wahlberg, Yu-Sheng Chen, Jacob Overgaard and Bo B. Iversen Contemporary X-ray electron-density studies using synchrotron radiation IUCrJ 2014 1 (5), 267-280 doi: 10.1107/S2052252514018570
