# Difference between revisions of "Optical resolution"

### From Online Dictionary of Crystallography

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− | <font color="blue">Pouvoir de résolution</font> (''Fr''). <font color="red">Bildauflösung</font> (''Ge''). <font color=" | + | <font color="blue">Pouvoir de résolution</font> (''Fr''). <font color="red">Bildauflösung</font> (''Ge''). <font color="black">Risoluzione angolare</font> (''It''). <font color="purple">分解能</font> (''Ja''). <font color="green">Resolución de imagen</font> (''Sp''). |

## Latest revision as of 09:49, 12 December 2017

Pouvoir de résolution (*Fr*). Bildauflösung (*Ge*). Risoluzione angolare (*It*). 分解能 (*Ja*). Resolución de imagen (*Sp*).

By analogy with optical observations, *e.g.* in astronomy, the term optical resolution in structure determination, [math]d_\mathrm{opt}[/math], is used to describe the expected minimum distance between two resolved peaks in an electron-density map.

[math]d_\mathrm{opt} = [2(\sigma_\mathrm{Patt}^2 + \sigma_\mathrm{sph}^2)]^{1/2}[/math]

where [math]\sigma_\mathrm{Patt}[/math] is the standard deviation of the Gaussian function fitted to the Patterson origin peak, [math]\sigma_\mathrm{sph}[/math] is the standard deviation of the Gaussian function fitted to the origin peak of the spherical interference function, representing the Fourier transform of a sphere with radius [math]1/d_\mathrm{min}[/math], and [math]d_\mathrm{min}[/math] is the nominal resolution.

## History

The term was introduced into the protein structure determination literature by Vaguine, A. A., Richelle, J. and Wodak, S. J. [(1999).
*Acta Cryst.* D**55**, 191-205. *SFCHECK: a unified set of procedures for evaluating the quality of macromolecular structure-factor data and their agreement with the atomic model*].