Direct methods - Revision history

BrianMcMahon: Tidied translations and added German and Spanish (U. Mueller)

2017-11-10T13:43:59Z

Tidied translations and added German and Spanish (U. Mueller)

BrianMcMahon: Edits to align with printed edition

2017-05-13T13:10:10Z

Edits to align with printed edition

BrianMcMahon at 12:03, 6 February 2012

2012-02-06T12:03:12Z

BrianMcMahon at 13:40, 29 March 2008

2008-03-29T13:40:12Z

MassimoNespolo at 08:59, 4 July 2007

2007-07-04T08:59:46Z

GiovanniFerraris: /* Other languages */

2006-03-17T15:27:40Z

‎Other languages

BrianMcMahon at 12:45, 25 January 2006

2006-01-25T12:45:48Z

New page

= Direct methods =

=== Other languages ===

Méthodes directes (''Fr'').

== Definition ==

<font color="red">Provide the definition of the entry (in English) here.</font>

=== See also ===

Section 2.2 of ''International Tables of Crystallography, Volume B''

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← Older revision		Revision as of 13:43, 10 November 2017
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−	<font color="blue">Méthodes directes</font> (''Fr''). <~~Font~~ color="black"> Metodi diretti </~~Font~~>(''It''). <font color="purple">直接法</font> (''Ja'').	+	<font color="blue">Méthodes directes</font> (''Fr''). <font color="red">Direkte Methode</font> (''Ge''). <font color="black">Metodi diretti</font> (''It''). <font color="purple">直接法</font> (''Ja''). <font color="green">Métodos directos</font> (''Sp'').

	== Definition ==		== Definition ==

@@ Line 1: / Line 1: @@
 <font color="blue">Méthodes directes</font> (''Fr''). <Font color="black"> Metodi diretti </Font>(''It''). <font color="purple">直接法</font> (''Ja'').
 == Definition ==
-The family of methods for solving the [[phase problem]] in crystal [[structure determination]]. The phases of scattered diffraction beams cannot be directly observed. However, they can be estimated from probability relationships applied to the phases of the most intense diffraction peaks. The facts that scattering centres in a crystal are discrete atoms (''i.e.'' sources of electron density) and that the electron density must be non-negative are the types of constraints that restrict the possible values of the phases, and allow initial estimates of some of them.
+A family of methods for estimating the phases of the Fourier transform of the scattering density from the corresponding magnitudes in crystal [[structure determination]]. The phases of scattered diffraction beams cannot be directly observed. However, they can be estimated from probability relationships applied to the phases of the most intense diffraction peaks. The facts that scattering centres in a crystal are discrete atoms (''i.e.'' sources of electron density) and that the electron density must be non-negative are the types of constraints that restrict the possible values of the phases, and allow initial estimates of some of them.
 == See also ==
-Direct methods.
+*Direct methods. C. Giacovazzo. ''International Tables for Crystallography'' (2008). ''Vol. B'', [https://doi.org/10.1107/97809553602060000764 ch. 2.2, pp. 215-243]
 [[Category: Structure determination]]

@@ Line 1: / Line 1: @@
 <font color="blue">Méthodes directes</font> (''Fr''). <Font color="black"> Metodi diretti </Font>(''It''). <font color="purple">直接法</font> (''Ja'').
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 The family of methods for solving the [[phase problem]] in crystal [[structure determination]]. The phases of scattered diffraction beams cannot be directly observed. However, they can be estimated from probability relationships applied to the phases of the most intense diffraction peaks. The facts that scattering centres in a crystal are discrete atoms (''i.e.'' sources of electron density) and that the electron density must be non-negative are the types of constraints that restrict the possible values of the phases, and allow initial estimates of some of them.
 == See also ==

@@ Line 3: / Line 3: @@
 === Other languages ===
-Méthodes directes (''Fr'').<Font color="black"> Metodi diretti </Font>(''It'')
+<font color="blue">Méthodes directes</font> (''Fr''). <Font color="black"> Metodi diretti </Font>(''It''). <font color="purple">直接法</font> (''Ja'').
 == Definition ==