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Difference between revisions of "Space group"

From Online Dictionary of Crystallography

(Factor group)
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<font color="blue">Groupe d'espace</font> (''Fr''); <font color="red">Raumgruppe</font> (''Ge''); <font color="black">Gruppo spaziale</font> (''It''); <font color="purple">空間群</font> (''Ja'').
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<font color="orange">صنف أو مجموعة الفضاء</font> (''Ar''). <font color="blue">Groupe d'espace</font> (''Fr''). <font color="red">Raumgruppe</font> (''Ge''). <font color="black">Gruppo spaziale</font> (''It''). <font color="purple">空間群</font> (''Ja''). <font color="brown">Кристаллографическая группа</font> (''Ru''). <font color="green">Grupo espacial</font> (''Sp'').
  
The symmetry group of a three-dimensional [[crystal pattern]] is called its '''space group'''. In ''E''<sup>2</sup>, the symmetry group of a two-dimensional crystal pattern is called its '''plane group'''. In ''E''<sup>1</sup>, the symmetry group of a one-dimensional crystal pattern is called its '''line group'''.
 
  
To each crystal pattern belongs an infinite set of translations '''T''', which are symmetry operations of that pattern. The set of all '''T''' forms a group known as the '''translation subgroup''' T of the space group G of the crystal pattern. T is an [[Abelian group]] and a [[normal subgroup]] of the space group. The [[factor group]] G/T of a space group G and its translation subgroup is isomorphic to the [[point group]] P of G.
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The symmetry group of a three-dimensional [[crystal pattern]] is called its '''space group'''. In ''E''<sup>2</sup>, the symmetry group of a two-dimensional crystal pattern is called its '''plane group''' (also known as ''wallpaper group''). In ''E''<sup>1</sup>, the symmetry group of a one-dimensional crystal pattern is called its '''line group'''.
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To each crystal pattern belongs an infinite set of translations '''T''', which are symmetry operations of that pattern. The set of all '''T''' forms a group known as the '''translation subgroup''' ''T'' of the space group ''G'' of the crystal pattern. ''T'' is an [[Abelian group]] and a [[normal subgroup]] of the space group. The [[factor group]] ''G/T'' of a space group ''G'' and its translation subgroup is isomorphic to the [[point group]] ''P'' of ''G''.
  
 
==See also==
 
==See also==
 
*[[Fixed-point-free space groups]]
 
*[[Fixed-point-free space groups]]
 
*[[Symmorphic space groups]]
 
*[[Symmorphic space groups]]
*Section 1.3 of ''International Tables for Crystallography, Volume A'', 6<sup>th</sup> edition
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*Chapter 1.3 of ''International Tables for Crystallography, Volume A'', 6th edition
  
 
[[Category:Fundamental crystallography]]
 
[[Category:Fundamental crystallography]]

Latest revision as of 13:37, 19 February 2021

صنف أو مجموعة الفضاء (Ar). Groupe d'espace (Fr). Raumgruppe (Ge). Gruppo spaziale (It). 空間群 (Ja). Кристаллографическая группа (Ru). Grupo espacial (Sp).


The symmetry group of a three-dimensional crystal pattern is called its space group. In E2, the symmetry group of a two-dimensional crystal pattern is called its plane group (also known as wallpaper group). In E1, the symmetry group of a one-dimensional crystal pattern is called its line group.

To each crystal pattern belongs an infinite set of translations T, which are symmetry operations of that pattern. The set of all T forms a group known as the translation subgroup T of the space group G of the crystal pattern. T is an Abelian group and a normal subgroup of the space group. The factor group G/T of a space group G and its translation subgroup is isomorphic to the point group P of G.

See also