Dear all, Although Custom geometry restrains was added (see log). After phenix refine, the link record was lost and there seem no bond between this two atoms (1.44 angstrom). Do you think this is a real bond? How to maintain this record? Any comment is appreciated! Best regards! Data resolution: 2.4 Phenix version:v2.7 phenix refine log: ======================== Summary of geometry restraints ======================= Number of disulfides: simple=1, symmetry=0 Simple disulfide: pdb=" SG CYS A 482 " - pdb=" SG CYS A 484 " distance=2.04 Custom bonds: bond: atom 1: "ATOM 1205 OG SER A 265 .*. O " atom 2: "HETATM 3413 C23 AIX A 700 .*. C " symmetry operation: x,y,z distance_model: 1.339 distance_ideal: 1.330 ideal - model: -0.009 slack: 0.000 delta_slack: -0.009 sigma: 0.2000 Total number of custom bonds: 1 Time building geometry restraints manager: 0.20 seconds pdb file LINK record: LINK OG SER A 265 C23 AIX A 700 1555 1555 -- Lu Zuokun, Ph.D. Candidate College of Life Science, Nankai University