Centric and acentric reflections: Difference between revisions

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Centric reflections play the same role in reciprocal space as special positions in real space: they may occur at the borders of the asymmetric unit. It makes sense to discuss the reciprocal case and the real space together.
Centric reflections play the same role in reciprocal space as special positions in real space: they may occur at the borders of the asymmetric unit. It makes sense to discuss the reciprocal case and the real space together.


A definition and a theorem about centric reflections are stated here [1] before the role of centrics is examined.
A definition and a theorem about centric reflections are stated here (see reference [1]) before the role of centrics is examined.


Definition: '''A reflection (h,k,l) is said to be centric if in the space group there is at least one symmetry operation g(x)=R_g*x+t_g whose rotational part R_g sends the reflection to minus itself''', i.e.:
Definition: '''A reflection (h,k,l) is said to be centric if in the space group there is at least one symmetry operation g(x)=R_g*x+t_g whose rotational part R_g sends the reflection to minus itself''', i.e.:
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