I think this is called P21, with the additional annoyance that you
need to pick your Rfree set in P212121 and then symmetry-expand it.
Otherwise, your NCS operators will constrain your free reflections
to have the same intensity as their NCS mates. I'm sure you didn't
make that mistake, but a lot
I am sure this has happened many many times before but I cannot find a
reference. I have a protein/DNA complex structure where the protein has
P212121 symmetry, but the DNA only has P21 symmetry. I know its
pseudosymmetry caused by the NCS. Has anyone seen this with protein/DNA
or have a
