[cctbxbb] 26-fold symm expansion of asu?

[Alastair Fyfe]

Hi,
I'd be grateful for any pointers to clipper or cctbx code that addresses 
the following: given a "brick" of map grid coordinates that enclose the 
asu, obtain the 26 symmetry-related "bricks" which contact it. 
Calculating this by successively generating symmetry mates and testing 
seems slow; I was wondering whether there was a better way.
thank you,
Alastair Fyfe
UCSC