Hi, I would like to calculate sa_omit map for a low resolution structure (4.0 Ang) to validate the conformation in some regions. What's the proper way to do it? Followed the instruction, I tried: phenix.autobuild data=mydata.mtz model=mybestmodel.pdb omit_box_pdb=mybestmodel.pdb \ omit_res_start_list=100 omit_res_end_list=200 omit_chain_list=L \ composite_omit_type=sa_omit I have several questions: 1. "omit_box_pdb=mybestmodel.pdb": If I define the region that I want to omit, do I need to define the omit_box pdb as well? Should it be complete model or the omit region? 2. I have 4 fold NCS axis, if I want to omit a loop in four copies, how can I define 4 corresponding regions in different chains? e.g omit region: 100-200 in chain L, M, N, O: omit_chain_list = L omit_chain_list = M omit_chain_list = N omit_chain_list = O omit_res_end_list = "200" omit_res_start_list = "100" 3. If I want to omit several loops in one copy, should I turn off NCS? Like: find_ncs=False input_ncs_file= None optimize_ncs=False 4. How to define several omit regions in one chain? Many thanks, Jin _________________________________________________________________ 上Windows Live 中国首页，下载最新版 MSN！ http://im.live.cn/