Any reciprocal lattice point (relp) not in the blind region will cross
the Ewald sphere twice. This is because it follows a closed circular
path that passes through a closed surface. Must be one "in" and one
"out". However, even in P1 there is always a Friedel mate, and that is
"symmetry equivalent" if you ignore anomalous scattering. This gives
you four "observations" for a given hkl index, provided you rotate the
full 360.
What you call "redundancy" is up to you.
-James Holton
MAD Scientist
On 8/15/2011 11:19 PM, john peter wrote:
Hi All,
I wish to confirm that when we collect native dataset 0-360 for a
protein crystal (P1 space group) , the redundancy could very well be
2 since many reciprocal points cross Ewald sphere twice, right ?
Thanks a lot.
John
