c2x and Visualising Symmetry with Mercury

Mercury is a large commercial package from the Cambridge Crystallographic Data Centre. It has a no-cost licence which permits the use of a subset of its features, and one can pay to unlock more functionality. The examples here use the free features.

Continuing from the symmetry overview page, one must note that the free functionality in mercury seems incapable of expanding a symmetry-inequivalent set of atoms from a cif file. Fortunately c2x can do this. Indeed, by default it leaves all atoms in a cif file. Either version can be downloaded from the links below.

  $ c2x --cif calcite.cif calcite_full.cif

Loading the structure into Mercury results in

Mercury with full calcite cell

after adjusting the zoom with Display | Dial Box | Zoom+.

The symmetry elements can be shown with Display | Symmetry Elements, but it does not seem possible to restrict the display to just one of a given class of operations.

Mercury with calcite's glide planes

Mercury with calcite's 2-fold axes

The symmetry operations can be listed with Display | More Information | Symmetry Operations List.

Mercury with calcite's symmetry operations

Back to the symmetry overview page.