Hello, I am wondering if pseudosymmetry can cause weak reflections that mimic the doubling of one unit cell axis' length. Has anyone seen something like this before?
I am processing data from a small molecule sample collected with electron diffraction from multiple crystals. For the b axis, it is not clear if the length should be 10A or 20A. There are spots with the correct spacing for b=20A, but every other spot seems weaker than the spots along k if I choose b=10A (this extends beyond (0,k,0)). I am unable to phase the b=20 data. I have solved this structure in P1 with b=10 and found four molecules in the ASU and in P212121 with b=10 resulting in one molecule in the ASU. In P1, three of the four molecules adopt the same conformation, but the fourth molecule is in an alternate conformation that causes only ~1/2 of the molecule to be consistent with the first three. In P212121 I see density for part of this alternative conformation, but the full molecule in this alternate conformation cannot pack properly in P212121. Based on these results and some orthogonal data, I think I should refine the solution in P1 with b=10. Does it seem reasonable that pseudosymmetry is causing these weak reflections along k hinting at a doubling of the b axis? Thanks in advance! Best, Jessica -- Jessica Bruhn, Ph.D Principal Scientist NanoImaging Services, Inc. 4940 Carroll Canyon Road, Suite 115 San Diego, CA 92121 Phone #: (888) 675-8261 www.nanoimagingservices.com ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
