Hi, Since the question was raised before, I think I know the answer to my first question about lattice translations but let me verify: 1) Chimera can apply crystallographic symmetry operations to the model as they're listed in the pdb file but it won't apply lattice translations, or in other words, won't display molecules in neighbouring unit cells. Am I correct ? maybe you can surprize me me on this and prove me wrong ? 2) Is it possible to draw the unit cell boundaries after reading in the pdb or should I read in a dummy pdb with coordinates of the unit cell vertices ? Cheers, Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan