[Ifeffit] space group P 4/mmc ?

[Bruce Ravel]

On 08/08/2014 03:33 PM, Marinkovic, Nebojsa wrote:
> Bruce,
> I found the PtO strucutre (WJ Moore, JACS 63 (1941) 1392) reported as P
> 4/m m c , but Atoms says "invalid space group".   Any clues?
> Thanks,
> Ned
>

Hi Ned,

I am CCing my answer to the Ifeffit Mailing List since I think this 
question of general interest.

The author is using archaic notation, which is a common problem with 
crystallography references from the early decades of the 20th century. 
"P 4/m m c" does not exist in the modern International Tables of 
Crystallography.  See
     http://en.wikipedia.org/wiki/List_of_space_groups

Happily the author also gives the Schoenflies notation.  "D^9_4h" is "P 
42/m m c" in modern notation.

The majority of the symbols Artemis recognizes are given in the Artemis 
Users' Guide:
    http://bruceravel.github.io/demeter/artug/atoms/space.html
although perhaps not in the most useful manner.  The wikipedia page is 
also useful for resolving a Schoenflies symbol to the corresponding 
Hermann-Maguin symbol.

You can also simply use the Schoenflies symbol in Artemis.  The string 
"D^9_4h" should be recognized by Atoms as the same as "P 42/m m c".

B


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

  National Institute of Standards and Technology
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