Centric and acentric reflections: Difference between revisions

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(h,k,l) is centric if there is a symop g(x)=R_g*x+t_g in G such that R_g*(h,k,l)=(-h,-k,-l)
(h,k,l) is centric if there is a symop g(x)=R_g*x+t_g in G such that R_g*(h,k,l)=(-h,-k,-l)
For example all reflection in the zone (h,k,0) are centrics in all space groups with twofold axes down c.


Theorem: '''The phase of a centric reflection is restricted to phi(h,k,l)=pi*(h*tx_g+k*ty_g+l*tz_g) plus or minus any integer number of pi'''
Theorem: '''The phase of a centric reflection is restricted to phi(h,k,l)=pi*(h*tx_g+k*ty_g+l*tz_g) plus or minus any integer number of pi'''
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