[cctbxbb] coordinates -> space group + matrices

[Jon Wright]

Kris Andersen wrote:
> This is probably a simple (maybe stupid) question, but that never  
> stopped me before:
> 
> I want to give cctbx a set of primitive vectors and coordinates  
> (cartesian or fractional), and have it return (1) the space group and  
> (2) all the symmetry matrices.
> 
> For example, given
> 
> R = [4 0 0    % primitive vectors
>       0 4 0
>       0 0 4]
> 
> x = [0.00  0.0   0.00   % fractional coordinates
>       0.51  0.51  0.51
>       0.50  0.50  0.00
>       0.00  0.50  0.50
>       0.50  0.00  0.50]
> 
> I want cctbx to tell me this is space group #160 R3m, that there are  
> 6 symmetry operations, and give me the corresponding matrices.

Hello,

Looks like the "F3m" setting, assuming all atoms are the same? Would you 
want to keep that or would you prefer it on the trigonal or hexagonal 
axes? Not sure if cctbx whether has a find symmetry algorithm, but there 
are a couple of other possibilities. Ton Spek's Platon software will 
read a structure in a cif file in space group P1 and then try to find 
the correct space group for you. Also there is Harold Stokes findsym 
program (http://stokes.byu.edu/findsym.html).

Good luck,

Jon

> This sounds easy, given everything cctbx can do, so it must be  
> possible. Is there a simple example anywhere?
> 
> Thanks.
> 
> --
> Kristopher E. Andersen         http://www.physics.nau.edu/~andersen/
> Northern Arizona University                    kris.andersen at nau.edu
> Department of Physics and Astronomy                   (928) 523-7202
> 
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