Dear all, I'm currently refining a small protein against 0.96A data using phenix.refine (1.6-486) from the GUI. Refinement without hydrogens yielded Rwork/free of 12.4/14.2. I then added H-atoms with phenix.reduce and switched to individual refinement of hydrogens which dropped the R-factors to 11.3/13.4. After this refinement the occupancies of some hydrogens dropped to 0 which makes me a little concerned. See e.g.: ATOM 752 H LYS A 45 -7.443 2.613 9.537 1.00 4.73 H ATOM 753 HA LYS A 45 -9.707 1.128 9.401 0.55 2.42 H ATOM 754 HB2 LYS A 45 -8.476 2.797 7.435 1.00 10.58 H ATOM 755 HB3 LYS A 45 -9.795 1.948 7.166 0.95 8.70 H ATOM 756 HG2 LYS A 45 -10.840 3.210 8.889 0.00 33.83 H ATOM 757 HG3 LYS A 45 -9.604 4.206 8.775 0.00 33.83 H ATOM 758 HD2 LYS A 45 -11.227 3.615 6.563 0.00 62.10 H ATOM 759 HD3 LYS A 45 -11.508 4.867 7.507 0.00 62.10 H ATOM 760 HE2 LYS A 45 -9.229 5.527 6.985 1.00 83.62 H ATOM 761 HE3 LYS A 45 -9.348 4.488 5.786 0.00 83.86 H ATOM 762 HZ1 LYS A 45 -10.909 5.758 4.853 1.00 99.63 H ATOM 763 HZ2 LYS A 45 -11.131 6.534 6.042 0.35100.44 H ATOM 764 HZ3 LYS A 45 -9.917 6.715 5.257 0.39100.08 H I would like to ask whether it is possible in phenix to group the occupancies to keep them at the same value as the rest of the residue but still refine xyz and isotropic adp of the individual hydrogens? Thank you in advance for your answers, Florian