Also try BALBES from the York site supplying the high symmetry data
and let it check things for you.
Sent from my iPhone
On 3 Jan 2009, at 14:40, James Holton <[email protected]> wrote:
You should pick your free-R set in C2221 and then symmetry-expand it
to C2. Otherwise, every hkl in your "free" R set will have an NCS
"mate" in the working set, and using NCS restrains will completely
invalidate the free R analysis. That is, your free-R will be
essentially equal to the regular crystallographic R and it will be
possible to take a completely wrong MR solution and refine it to an
"acceptable" free R, and if you do that, we will all make fun of you.
-James Holton
MAD Scientist
Yu Jiang wrote:
Dear all,
I am now refining one structure in space group C2 with 2 molecules,
however we find the data can be processed in C2221 with 1 molecule.
The questions are:
1. Can I still use space group C2 instead of C2221, even if the two
molecules almost have crystallographic symmetry? Should I provide
any excuses?
2. Is there any indication or necessity to refine structures in
lower space group instead of higher?
Many thanks!
