thus I am relying to the CCP4i libraries to return to me the correct space group name when the user reads in a file.
set space_group [GetSpaceGroupNumber $array(SPACE_GROUP)]
that is because ARP/wARP programs want to use space group numbers as input later on.
So, whatever the error is with C121 and P121 is not in ARP/wARP. Very likely it is in the GetSpaceGroupNumber function of CCP4i.
You can easily check that, since under 'Crystal Parameters' the space group name should be 'P121', but I suspect that for that
I get a '0' for space group number... (would be good if somebody sends me such a file so I can check!)
Thus, the 'ARP/wARP people' cannot fix, no matter how willing they are. However, I would appreciate if
somebody from CCP4 team tells me if there is something wrong in the code,
or fixes the CCP4i code if it is indeed broken for that function.
Also, yet another solution if anyone runs to this problem, is to run
auto_tracing.sh
from the command line (it will list a choice of needed keywords)
That uses a program by the ARP/wARP team that will figure out the correct space group number from the symmetry operators of the MTZ file and it should run in C121 just like C2.
The same is true for the ARP/wARP Hamburg Web Server.
Best -
Tassos