Re: [ccp4bb] Friedel vs Bijvoet

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

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Subject: Re: Friedel vs Bijvoet
From: Dale Tronrud det102 {- at -} UOXRAY {- dot -} UOREGON {- dot -} EDU
Date: 2008-06-27

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Subject: Re: Friedel vs Bijvoet
From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
Date: 2008-06-27

Subject: Re: Friedel vs Bijvoet
From: Dale Tronrud det102 {- at -} UOXRAY {- dot -} UOREGON {- dot -} EDU
Date: 2008-06-27

Bernhard Rupp wrote:
> I quote from these pages:
>
> "Bijvoet pairs are Bragg reflections which are true symmetry
> equivalents to a Friedel pair. These true symmetry equivalents
> have *equal amplitudes, even in the presence of anomalous scattering*."

This is poorly worded. I would change it to

A Bijvoet MATE IS A Bragg reflection which IS A true symmetry
equivalent to THE Friedel MATE OF SOME OTHER REFLECTION. These true symmetry equivalents
have *equal amplitudes, even in the presence of anomalous scattering*.

Note that the Bijvoet mate is symmetry related to the Friedel mate
not the original reflection.

Dale Tronrud

>
> Sounds more like centric or perhaps simply symmetry related to me.
>
> A few lines below:
>
> " A Bijvoet difference refers to the difference in measured
> amplitude for a Bijvoet pair"
>
> I don't think you can have it both ways ??
>
> BR

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Friedel vs Bijvoet
From: Dale Tronrud det102 {- at -} UOXRAY {- dot -} UOREGON {- dot -} EDU
Date: 2008-06-27

Next message:
Subject: Re: Friedel vs Bijvoet
From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
Date: 2008-06-27