• Symmetry of Wyckoff position


    I have a question concerning finding Wyckoff position of molecules in the asymmetric unit along with the symmetry of this position. The only function which I have found in API that could be useful is crystals.atoms_on_special_positions which gives information about the atoms lying on Wyckoff position. Unfortunately, this function returns information only when atom lies on the symmetry element but it does not consider a possibility that a molecule has symmetry of Wyckoff position (different than 1) and no atom lies on the symmetry element. 

    The other thing is information about the symmetry of this position. I am aware that I can get information about the symmetry operator but it does not directly inform about the symmetry of the special position which can be just -1 or sth more complicated as 222, 4/m etc. 

    Are you aware of any function implemented in CSD API which could help both finding Wyckoff position and its symmetry?

    Thank you in advance,




  • Adding atoms as donors/acceptor to hbonds of crystal


    I was looking for an option to define a new donor/acceptor when using Crystal.hbonds 

    Unfortunately with default version carbon is not specified as an atom that can participate in hydrogen bonds.


    Is there any way to change that?

    Thank you in advance for an answer.