Dear Crystallographers, I don't understand what the 1's are doing in space group names like P3212 or P3112--can someone fill me in? Not easy to google this one. JPK ******************************************* Jacob Pearson Keller, PhD Looger Lab/HHMI Janelia Research Campus 19700 Helix Dr, Ashburn, VA 20147 email: [log in to unmask] *******************************************