john kryst wrote:
> Hi all !!!
>
> I am sorry for a dumb question.
not really :)
> I am using save_symmetry_coords command (const char *filename, int
> imol, int symop_no, int shift_a, int shift_b, int shift_c, int
> pre_shift_to_origin_na, int pre_shift_to_origin_nb, int
> pre_shift_to_origin_nc)
>
> I am not able to get what is pre_shift_to_origin_na.. Someone please
> help in identify this.. How will get this information for the
> molecule of interest in coot.
>
Some of Coot's interal operations are exposed here. In order to
generate symmetry at a general position, the molecule is moved
(virtually) to the origin, then the symmetry expansion takes place, then
the symmetry copies are moved back to the place of interest. The
pre_shift_to_origins are the number of unit cell lengths along a, b and
c, that need to be applied to bring the centre of the molecule as close
as possible to the origin. Quite often, I'd imagine that those numbers
are 0,0,0. In the general case you would have to compare the molecule
centre with the unit cell. Now that I loook for it, I see that there is
not a function that returns the unit cell. Hmm... Oh dear. well, I'll
have to address that.
Hope that helps,
Paul.
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