Dear All,
I am working with a data set which seems to be orthorhombic. The self rotation function maps in P1 clearly show a 222 symmetry. Even mosflm detect easily an orthorhombic space group. The fst problems is that the systematic presences are rare: h00 are clearly 2n; 0k0 in bits seems to be 4n and in other bits 2n; in there is nothing in 00l. I was hesitating between P2(1)22 or P2(1)2(1)2. Surprisingly (at least for me), when I try to solve the MR with Phaser (using a model which is 60 % identical in sequence), the best solution was in P2(1)2(1)2(1), with a trimer in the AU. However the refinement never produces something better than models with R values around 35% (and the map seems to be very clear). The resolution is 2.2 A and I collected 360 degrees with 1 degree between them…any idea of how can I explain the behavior of the systematic absences? Thank you in advance. Dr. Enrique Rudino
