Electron density map - Revision history

BrianMcMahon: Tidied translations and corrected German (U. Mueller)

2017-11-13T09:43:19Z

Tidied translations and corrected German (U. Mueller)

BrianMcMahon: Style edits to align with printed edition

2017-05-13T13:55:02Z

Style edits to align with printed edition

MassimoNespolo: lang

2015-03-20T04:43:47Z

lang

BrianMcMahon at 09:21, 3 April 2008

2008-04-03T09:21:30Z

New page

== Definition ==

A three-dimensional description of the electron density in a crystal structure, determined from X-ray diffraction experiments. X-rays scatter from the electron clouds of atoms in the crystal lattice; the diffracted waves from scattering planes <math>h, k, l</math> are described by [[structure factor]]s <math>\mathbf{F}_{hkl}.</math> The electron density as a function of position <math>x,y,z</math> is the Fourier transform of the structure factors:

<math>\rho(xyz) = {1\over V}\sum_{hkl} F(hkl)\exp[-2\pi i(hx + ky + lz)]</math>.

The electron density map describes the contents of the unit cells averaged over the whole crystal and not the contents of a single unit cell (a distinction that is important where structural disorder is present).

Three-dimensional maps are often evaluated as parallel two-dimensional contoured sections at different heights in the unit cell.

== Units ==

Electron density is measured in electrons per cubic ångström, e Å<sup>-3</sup>.

[[Category:Structure determination]]
[[Category:X-rays]]

← Older revision		Revision as of 09:43, 13 November 2017
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−	<~~Font~~ color="blue">Carte de densité électronique </Font>(''Fr''). <~~Font~~ color="red">~~Elektron-Dichte~~-Karte</~~Font~~> (''Ge''). <~~Font~~ color="~~green~~">~~Mapa de densidad electrónica~~</~~Font~~> (''Sp''). <~~Font~~ color="~~black~~"> ~~Mappa di densità elettronica~~</~~Font~~> (''It''). <~~Font~~ color="~~purple~~">~~電子密度図~~</~~Font~~> (''Ja'').	+	<font color="blue">Carte de densité électronique</Font> (''Fr''). <font color="red">Elektronendichte-Karte</font> (''Ge''). <font color="black">Mappa di densità elettronica</font> (''It''). <font color="purple">電子密度図</font> (''Ja''). <font color="green">Mapa de densidad electrónica</font> (''Sp'').

@@ Line 1: / Line 1: @@
-<Font color="blue">Carte de densité électronique </Font>(''Fr''). <Font color="red">
+<Font color="blue">Carte de densité électronique </Font>(''Fr''). <Font color="red">Elektron-Dichte-Karte</Font> (''Ge''). <Font color="green">Mapa de densidad electrónica</Font> (''Sp''). <Font color="black"> Mappa di densità elettronica</Font> (''It''). <Font color="purple">電子密度図</Font> (''Ja'').
 == Definition ==
-A three-dimensional description of the electron density in a crystal structure, determined from X-ray diffraction experiments. X-rays scatter from the electron clouds of atoms in the crystal lattice; the diffracted waves from scattering planes <math>h, k, l</math> are described by [[structure factor]]s <math>\mathbf{F}_{hkl}.</math> The electron density as a function of position <math>x,y,z</math> is the Fourier transform of the structure factors:
+A three-dimensional description of the electron density in a crystal structure, determined from X-ray diffraction experiments. X-rays scatter from the electron clouds of atoms in the crystal lattice; the diffracted waves from scattering planes <math>h, k, l</math> are described by [[structure factor]]s <math>\mathbf{F}_{hkl}.</math> The electron density as a function of position <math>x, y, z</math> is the Fourier transform of the structure factors:
 <math>\rho(xyz) = {1\over V}\sum_{hkl} F(hkl)\exp[-2\pi i(hx + ky + lz)]</math>.
@@ Line 16: / Line 14: @@
 == Units ==
-Electron density is measured in electrons per cubic &aring;ngstr&ouml;m, e &Aring;<sup>-3</sup>.
+Electron density is measured in electrons per cubic &aring;ngstr&ouml;m, e &Aring;<sup>&minus;3</sup>.
 [[Category:Structure determination]]
 [[Category:X-rays]]

← Older revision		Revision as of 04:43, 20 March 2015
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		+	<Font color="blue">Carte de densité électronique </Font>(''Fr''). <Font color="red">
		+	Elektron-Dichte-Karte</Font>　(''Ge''). <Font color="green">Mapa de densidad electrónica</Font> (''Sp''). <Font color="black"> Mappa di densità elettronica</Font> (''It''). <Font color="purple">電子密度図</Font>　(''Ja'')
		+
		+
		+
	== Definition ==		== Definition ==