We run into an interesting space group problem. The same diffraction image can be either indexed into space group C2, with a=145, b=44, c=67, and beta=110.5; or space group P2 (should be P21 after scaling), with a=67, b=44, c=136, and beta=96.8. Both are refined ok during index. These two must somehow be related. Can anyone give some comments on that?

Thanks a lot,

Junyu