Re: [ccp4bb]: magic angle

[Paul Hubbard <phubbard@post.its.mcw.edu>]

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I think it comes from solid state NMR, where the crystal is oriented at 54.7
degrees to eliminate dipolar effects in an NMR spectrum (at least that what
I heard in an NMR course).

54.7 degrees = arccos root (1/3)

which comes from 1-3cos(^2)theta = 0. Which comes from something else.

AGS.

marius wrote:

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> Can someone explain to me (in simple words) the pratical
> and theoretical usefullness of a diffractometer with kappa
> geometry with magic angle (54.? deg) using pre-oriented
> and randomly oriented crystals.
>
> Best regards
> Marius
>
> _____________________________________________________________________________
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> Dr. Marius Schmidt
> Physikdepartment E17
> Technische Universitaet Muenchen
> James Franck Strasse
> 85748 Garching
>       Germany
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