[Ifeffit] Ifeffit Digest, Vol 169, Issue 9

[Bruce Ravel]

On 03/14/2017 06:15 AM, Abhinav Prabhakar wrote:
> Attached is the CIF file in question. The crystal is Tobermorite 14A,
> taken from COD website.
>

Abhinav,

I don't understand the contents of the CIF file in the context of the 
copy of the International Tables that I have in front of me.  The list 
of equivalent positions given in the CIF file just doesn't seem to be 
right for space group 9.

The CIF file is clearly using the C axis as the unique axis since the z 
coordinate is the negated coordinate.  But the list of positions does 
not correspond to any of the three cell choices.

While this could be a problem in Artemis, I am inclined to think that 
the authors of the paper cited in the CIF file made some kind of 
non-standard choice for the setting of their crystal.

As I said before, Artemis does what the International Tables tell it to 
do.  If the author of a crystallography paper makes some non-standard 
choice, Artemis won't know how to deal with it.

B



-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS-II
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