On 10/02/14 21:46, Yong Wang wrote:
Dear Coot users,
The symmetry operator in the new Coot (0.7.2) has a different style from that in the older
version. For example, the current symmetry operator (based on the label) would have something
like -X+Y,-X,Z+(1 1 0)&{0 1 0} and the saved coordinates file would be named
xxxx_symmetry_3010100.pdb. The translational part does not look as simple as the old style.
Could someone explain the part "+(1 1 0)&{0 1 0}"? Is there a command to export
the matrix out?
Dear Yong,
I don't know how other programs do symmetry expansion, but Coot moves
the molecules close to the origin (by cell translations), does the
symmetry expansion there and then moves everything back around where the
origin molecule was placed. The vector after the & shows the necessary
origin-shift needed to bring the molecule close to the origin.
In the past, the atom symmetry label was the sum of the actual
translation (due to symmetry operator) and the pre-translation. Some
time ago I decided that that, although shorter, was confusing.
I don't think that there is a function to write out symmetry matrices
explicitly, but I suppose that it would be straightforward to write to
the screen the symmetry operator of the selected symmetry molecule when
you write a symmetry related file. Would that do?
Paul.
